Method for fabricating structure

Abstract

To provide a method for fabricating a structure capable of expanding an angle of light incidence for exposure.SOLUTION: A method for fabricating a structure involves arranging a waveguide device 13, a mask device 15, and a photosensitive resin body 49 sequentially in the direction of a first axis, wherein the mask device 15 has a mask pattern 47, and a prism device 29 within the waveguide device 13 has an incident surface 29b and an exit surface 29c, and the incident surface 29b and the exit surface 29c of the prism device 29 are arranged to form a prism structure. The method includes arranging the waveguide device 13, the mask device 15, and the photosensitive resin body 49, and irradiating a light beam from the mask device 15 onto the photosensitive resin body 49 through the exit surface 13b of the waveguide device 13 and the mask pattern 47. The irradiation is performed while relatively rotating the photosensitive resin body 49 and the mask device 15 around the first axis with respect to the waveguide device 13, and involves irradiating the photosensitive resin body 49.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to methods of making structures. [Background technology]

[0002] Patent Document 1 discloses a method for producing a microstructure, which can form a microstructure with a complex three-dimensional shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5458241 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a method for producing a microstructure, in which light is irradiated onto a mask at an oblique angle relative to the mask and photosensitive resin, and the photosensitive resin is exposed to light while the mask and photosensitive resin are rotated.

[0005] While tilting the incident light makes it possible to form complex three-dimensional shapes, light is refracted and reflected according to the law of reflection and refraction when it enters and leaves an object, such as a mask or photosensitive resin, located on the path of the incident light. The reflection of light reduces the amount of light that reaches the photosensitive resin and changes depending on the tilt angle.

[0006] If it were possible to increase or decrease the inclination of the incident light, that is, to change the angle of incident light over a wide range, it would be easier to fabricate a variety of microstructures.

[0007] The present disclosure aims to provide a method for fabricating a structure that allows for a wide angle of light incidence for exposure. [Means for solving the problem]

[0008] A method for fabricating a structure according to a first aspect of the present invention includes arranging a waveguide device, a mask device, and a photosensitive resin body in the direction of a first axis, wherein the mask device has a mask pattern that defines light transmission, and the waveguide device includes a prism device, the prism device having an incident surface configured to receive light from a light source and an exit surface configured to emit the light, the incident surface and the exit surface of the prism device being arranged to form a prism structure; and irradiating the photosensitive resin body with a beam of light through the exit surface of the waveguide device and the mask pattern of the mask device, wherein the irradiation is performed while rotating the photosensitive resin body and the mask device relative to the waveguide device around the first axis, and irradiating the photosensitive resin body with the beam of light, wherein the irradiation to the photosensitive resin body is performed from a direction inclined at a first angle with respect to the first axis. [Effects of the Invention]

[0009] According to the above aspect, there is provided a method for producing a structure that can widen the angle of light incidence for exposure. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a partially cutaway view that schematically shows the structure of an exposure apparatus according to this embodiment. [Figure 2] Figure 2(a) is a diagram showing part of the structure of an exposure apparatus according to this embodiment, and Figure 2(b) is a diagram showing part of the structure of an exposure apparatus according to this embodiment. [Figure 3] Figure 3(a) is a diagram showing part of the structure of an exposure apparatus according to this embodiment, and Figure 3(b) is a diagram showing part of the structure of an exposure apparatus according to this embodiment. [Figure 4] Figure 4(a) is a diagram showing part of the structure of an exposure apparatus according to this embodiment, and Figure 4(b) is a diagram showing part of the structure of an exposure apparatus according to this embodiment. [Figure 5] 5(a) and 5(b) are diagrams showing the main steps in a method for fabricating a structure according to this embodiment. [Figure 6] FIG. 6 is a diagram showing the relationship between the inclination and rotation of a light beam and the shape of a structure when a photosensitive resin body is exposed using a prism and two masks. [Figure 7] FIG. 7 is a diagram showing the relationship between the inclination and rotation of the light beam and the shape of the structure when exposing a photosensitive resin body using two masks. [Figure 8] 8(a) and 8(b) are schematic diagrams showing structures after exposure and development through the masks of FIGS. 6 and 7, respectively. [Figure 9] FIG. 9 is a diagram showing the main steps in a method for producing a retroreflector according to this embodiment. [Figure 10] Part (a) of Figure 10 is a diagram showing an exemplary mask for a retroreflector, and parts (b), (c), and (d) of Figure 10 are scanning electron microscope (SEM) images of developed resist for the retroreflector. [Figure 11] Figure 11(a) shows the relationship between the exposure dose for fabricating a retroreflector and the structural dimensions of the fabricated retroreflector, and Figure 11(b) shows the relationship between the structural spacing of the fabricated retroreflector and the pixel value of the retroreflector. [Figure 12] FIG. 12 is a diagram showing the main steps in a method for fabricating an electrode base and an electrode for frictional power generation according to this embodiment. [Figure 13] Part (a) of Fig. 13 is a diagram showing an exemplary mask for a microstructured electrode base, and parts (b), (c), and (d) of Fig. 13 are scanning electron microscope (SEM) images of a molded resin body for the electrode base fabricated using the exemplary mask. [Figure 14] FIG. 14 is a diagram showing a schematic diagram of a system for measuring the power generation characteristics of a friction power generation device. [Figure 15]FIG. 15 is a diagram showing a schematic diagram of a frictional power generation device using micro-structured electrodes. [Figure 16] FIG. 16 is a diagram schematically showing deformation of protrusions in a flexible microstructure such as silicone rubber. [Figure 17] FIG. 17 is a diagram showing the output waveform of a typical power generating device for a typical charging material. [Figure 18] FIG. 18 is a diagram showing the relationship between the angle at which the exposure light is applied to form the microstructure and the structural angle of the microstructure thus formed. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same parts are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0012] FIG. 1 is a partial cutaway view that schematically shows the structure of an exposure apparatus according to this embodiment. FIG. 2(a) is a drawing that shows a portion of the structure of an exposure apparatus according to this embodiment. FIG. 2(b) is a drawing that shows a portion of the structure of an exposure apparatus according to this embodiment. FIG. 3(a) is a drawing that shows a portion of the structure of an exposure apparatus according to this embodiment. FIG. 3(b) is a cross-sectional view taken along line IIIb-IIIb shown in FIG. 3(a) that shows a portion of the structure of an exposure apparatus according to this embodiment. FIG. 4(a) is a cross-sectional view taken along line IIIb-IIIb shown in FIG. 3(a) that shows a portion of the structure of an exposure apparatus according to this embodiment. FIG. 4(b) is a cross-sectional view taken along line IIIb-IIIb shown in FIG. 3(a) that shows a portion of the structure of an exposure apparatus according to this embodiment. A coordinate system CS that indicates the orientation of the exposure apparatus is depicted in FIGS. 2(a), 2(b), and 3(a).

[0013] The exposure apparatus 11 includes a waveguide device 13 , a housing structure 17 , a driver 21 , a fixing device 23 , a support base 25 , and a support table 27 .

[0014] In FIG. 1, the housing structure 17 is partially cut away along a vertical cross section including the rotation axis Rx, so that the connection between the support base 27 and the actuator 21 is clearly shown. In FIG. 2(a), components of the exposure apparatus 11 are removed so that the mask device 15 and the support base 27 are clearly shown. In FIG. 2(b), components of the exposure apparatus 11 are removed so that the housing structure 17 is clearly shown. In FIG. 3(a), components of the exposure apparatus 11 are removed so that the waveguide device 13 is clearly shown. In FIG. 3(b), the exposure apparatus 11 is cut away along a vertical cross section including the first axis (hereinafter referred to as the "rotation axis Rx" in the embodiments) and the Yr axis of FIG. 3(a) so that the structures of the housing structure 17 and the mask device 15 are clearly shown. In FIG. 4(a), the exposure apparatus 11 is cut away along a vertical cross section including the rotation axis Rx so that the support base 27 in the housing structure 17 is clearly shown. In FIG. 4(b), the object to be exposed and the mask device 15 are placed on the support table 27 shown in FIG. 4(a).

[0015] Referring to FIG. 1 , in the exposure apparatus 11, the fixing device 23 is fixed to a support base 25. On the support base 25, the actuator 21 and the fixing device 23 are arranged in the direction of the arrangement axis Arx. In the exemplary exposure apparatus 11, the actuator 21, the fixing device 23, and the support base 25 are arranged in the direction of the arrangement axis Arx. The fixing device 23 supports the actuator 21. While supported by the fixing device 23, the actuator 21 is tiltable with respect to a base normal axis Ax1 (or the arrangement axis Arx) of the main surface 25b of the support base 25. The rotation shaft 21b of the actuator 21 extends along the rotation axis Rx and is rotatable around the rotation axis Rx, for example, in the direction of the arrow 28. The housing structure 17 is fixed to the actuator 21 so as to be spaced apart from the rotation shaft 21b. The support base 27 is supported by the rotation shaft 21b of the actuator 21 and rotated by the actuator 21. The support table 27 has a main surface 27b on which a workpiece 35 (see FIG. 4(b)) is placed. The workpiece 35 may include, for example, a photosensitive resin body.

[0016] 1 and 2(a), the housing structure 17 has a recess 18 shaped to accommodate the support base 27. The exemplary recess 18 is formed by a bottom plate 18b and a side wall 18c. The exemplary bottom plate 18b and the side wall 18c can be configured to form the recess 18. The exemplary bottom plate 18b is supported by the driver 21 and has a through hole 18d. The rotation shaft 21b of the driver 21 reaches the support base 27 through the through hole 18d and transmits the rotational drive of the driver 21 to the support base 27. The through hole 18d is hermetically sealed by the housing of the driver 21 and the bottom plate 18b. The exemplary side wall 18c is provided on an edge of the bottom plate 18b and extends from the bottom plate 18b in the direction of the rotation axis Rx. The exemplary side wall 18c has an upper end 18f at a position higher than the height of the main surface 27b of the support base 27 in the direction of the rotation axis Rx. Upper end 18f defines opening 18h. Light used for exposure passes through opening 18h and reaches workpiece 35 (see FIG. 4(b)) on support table 27.

[0017] 1 and 2(b), the housing structure 17 also includes a cover member 18g, which is disposed to cover the opening 18h of the recess 18. The exemplary cover member 18g is located on the upper end 18f of the side wall 18c and is positioned by the support structure of the side wall 18c. The side wall 18c and the cover member 18g hermetically seal the recess 18.

[0018] The main portion of the cover member 18g, specifically the area through which the light used for exposure passes, can be made of a material that can transmit light in the wavelength range of the exposure light.

[0019] 1, 3(a) and 3(b), the waveguide device 13 has an incident surface 13b configured to receive light used for exposure and an exit surface 13c configured to emit the incident light. The main part of the waveguide device 13, specifically the area through which the exposure light passes, can be made of a material that can transmit light in that wavelength band.

[0020] The exemplary waveguide device 13 may include a prism device 29 having an incident surface 29b configured to receive light used for exposure and an exit surface 29c configured to emit the received light. The incident surface 29b and the exit surface 29c of the prism device 29 are arranged to form a prism structure. A main portion of the prism structure, specifically, a region through which the light used for exposure passes, may be made of a material that is transparent to light in that wavelength band.

[0021] The prism structure provides the exposure apparatus 11 with an angle (tilt angle, e.g., less than 90 degrees) between the entrance surface 29b and the exit surface 29c, which is referred to as a prism angle (third angle ANG3). An exemplary prism structure may be a so-called triangular prism, in which the cross section of the prism structure is substantially triangular. However, the prism device 29 is not limited to a triangular prism.

[0022] Light used for exposure is incident on incident surface 29b of prism device 29 from an air region at a certain incident angle. This incident light propagates within prism device 29 at an angle relative to incident surface 29b (a refraction angle different from the incident angle) according to the laws of reflection and refraction at incident surface 29b. This propagated light reaches (is incident on) exit surface 29c of prism device 29 at a certain arrival angle. The propagated light is refracted at exit surface 29c according to the laws of reflection and refraction, becoming exit light that is emitted from exit surface 29c at a certain exit angle.

[0023] The sum of the refraction angle and the arrival angle is equal to the prism angle. The deflection angle of the prism device 29 is defined by the arithmetic value of the sum of the incident angle relative to the entrance surface 29b and the exit angle relative to the exit surface 29c minus the prism angle.

[0024] In an exemplary prism structure, prism device 29 may include one or more total internal reflection surfaces disposed between entrance surface 29b and exit surface 29c. Light from entrance surface 29b is reflected by the total internal reflection surfaces and propagates within prism device 29 to reach exit surface 29c. In the prism structure, entrance surface 29b and exit surface 29c may be configured such that the sum of the refraction angle at entrance surface 29b and the arrival angle at exit surface 29c is equal to the prism angle.

[0025] As shown in FIG. 1, the incident surface 13b of the waveguide device 13 is irradiated with light used for exposure by a light source SC of the exposure apparatus 11. The irradiated light from the light source SC is incident on the incident surface 13b from a direction inclined with respect to the normal axis (Nrx in FIG. 1) of the incident surface 13b. The exemplary light source SC is oriented with respect to the incident surface 29b of the prism device 29, and the angle of the incident light to the prism device 29 is specified with respect to the normal axis (Nrx in FIG. 1) of the incident surface 13b. Specifically, the orientation of the light source SC includes orienting the output axis of the light source SC with respect to the incident surface 29b of the prism device 29 so that the incident angle of the light with respect to the incident surface 29b of the prism device 29 can be specified.

[0026] The exposure apparatus 11 has a guide structure 33 that allows alignment of the waveguide device 13 and the housing structure 17. Although an exemplary guide structure 33 has a pin structure, the shape of the guide structure 33 is not limited thereto and can include, for example, one or more guide surfaces.

[0027] 1 and 4(b), the rotation axis Rx is inclined at a second angle ANG2 with respect to the base normal axis Ax1. In a waveguide device 13 that does not include a prism device 29, the light for exposure is incident on the photosensitive resin body 49 of the workpiece 35 at an incident angle associated with the angle (ANG2). By using the prism device 29, the incident angle (first angle ANG1) on the photosensitive resin body 49 can be increased.

[0028] 1 and 3(b), the exemplary waveguide device 13 may include a prism holder 37 that positions the prism device 29 relative to the housing structure 17. The prism holder 37 may include one or more guide surfaces 37b that guide the prism device 29, and the guide surfaces 37b may extend along a second axis Rx2 that is orthogonal to the rotation axis Rx.

[0029] At least one of the exemplary prism holder 37 and the lid member 18g, for example, the prism holder 37, can have a recess 39. In the exposure apparatus 11, the recess 39 accommodates the second mask device 31. The prism holder 37 and the lid member 18g can be configured such that the recess 39 is hermetically sealed. The exemplary second mask device 31 includes a mask base 41 and a mask pattern 43 provided on a major surface 41b of the mask base 41. The second mask device 31 and the mask base 41 have a back surface 41c on the opposite side to the major surface 41b of the mask base 41.

[0030] The mask pattern 43 of the second mask device 31 defines a processing pattern of the workpiece 35 (see FIG. 4(b)). The second mask device 31 is attached to the exposure tool 11 and is used depending on the exposure pattern.

[0031] An exemplary second mask device 31 can be arranged as follows: The second mask device 31 is disposed in contact with the exit surface 29c (13c) of the prism device 29 and / or the second mask device 31 is disposed in contact with the outer surface 18j of the cover member 18g. Alternatively, the second mask device 31 can be provided between the exit surface 29c (13c) of the prism device 29 and the outer surface 18j of the cover member 18g. In these arrangements, the second mask device 31 does not rotate.

[0032] An exemplary mask pattern 43 can be provided on the exit surface 29c (13c) of the prism device 29.

[0033] 4(a) and 4(b) are drawings showing the support base of the exposure apparatus according to this embodiment.

[0034] 4(a) and 4(b), there is shown a support table 27 (stage) configured to mount a support 48. The support table 27 is rotatably placed within the recess 18.

[0035] In the exposure apparatus 11, the mask device 15 and the workpiece 35 are mounted on a support table 27. The mask device 15 has a mask base 45 and a mask pattern 47, and the mask pattern 47 is provided on a major surface 45b of the mask base 45. The mask device 15 and the mask base 45 have a back surface 45c on the opposite side to the major surface 45b, and the back surface 45c receives light for exposure.

[0036] The recess 18 accommodates the mask device 15. The mask device 15 has a mask pattern 47 that defines a processing pattern of the workpiece 35. The mask device 15 is attached to the exposure tool 11 and is used in accordance with the exposure pattern.

[0037] The mask device 15 and the workpiece 35 are placed in the recess 18. The workpiece 35 includes a support 48 and a photosensitive resin body 49, and the photosensitive resin body 49 is provided on the main surface of the support 48. The support 48 is mounted on the main surface 27b of the support table 27.

[0038] The exemplary mask device 15 can be disposed in close contact with the photosensitive resin body 49. Specifically, the mask pattern 47 of the mask device 15 is positioned relative to the rotation axis Rx.

[0039] As previously described, the mask device 15 has a mask pattern that defines a processing pattern for the workpiece 35. The exemplary mask device 15 is placed over the workpiece 35 in the recess 18 of the housing structure 17. The mask device 15, the support table 27, and the workpiece 35 are rotated together by the driver 21.

[0040] In the exposure device 11, a refractive index matching material such as immersion oil can be placed in the recess 18 and the concave portion 39.

[0041] Specifically, the mask device 15, the support table 27, and the workpiece 35 are placed in the recess 18, and these are rotated together by the driver 21. For this reason, it is preferable that the recess 18 be filled with a refractive index matching material that enables this rotational movement without generating air bubbles.

[0042] On the other hand, the second mask device 31 can be placed in the recess 39. The recess 39 is filled with a refractive index matching material regardless of whether the second mask device 31 is present. In order to reduce unwanted light scattering, it is preferable that the refractive index matching material is filled in the recess 39 without creating bubbles. In exposure that does not use the second mask device 31, the exposure apparatus 11 does not need to be provided with the recess 39.

[0043] Also, the second mask device 31 can be selectively used and is housed in a recess 39 as shown in Fig. 3(b). Specifically, the second mask device 31 is fixed to the exposure apparatus 11, while the mask device 15 is rotated. The position of the second mask device 31 is fixed. The opening pattern of the second mask device 31 acts as a light transmitting portion and can also control the timing of light distribution to the rotating mask device 15.

[0044] The driver 21 is tiltable with respect to the base normal axis Ax1 (or the arrangement axis Arx) of the main surface 25b of the support base 25 while being supported by the fixing device 23, so that the irradiation of the photosensitive resin body 49 is performed along a direction (irradiation axis FLx) tilted with respect to the rotation axis Rx. In an exemplary arrangement in which the rotation axis Rx is the normal axis with respect to the incident surface of the mask device 15, the irradiation of the photosensitive resin body 49 forms a first angle ANG1 with respect to the irradiation axis FLx.

[0045] When a refractive index adjusting material is provided in the depression 18 and the recess 39, light from the exit surface 29c of the prism device 29 passes through an object such as glass or transparent resin material having a refractive index greater than that of air, and reaches the workpiece 35 while avoiding passing through a medium such as air.

[0046] As described above, in the exposure apparatus 11, the housing structure 17 is configured as a support structure to support the waveguide device 13. The housing structure 17 is also provided as a container structure. The housing structure 17 is configured to support the mask device 15 and the photosensitive resin body 49 so that they can rotate about the rotation axis (Rx) relative to the waveguide device 13, and to enclose and house the mask device 15 and the photosensitive resin body (49). The driver 21 is attached to the container structure so that it can rotate the mask device 15 and the photosensitive resin body 49 within the container structure. The light source SC is oriented so that it can be tilted at an angle with respect to the incident surface 13b of the waveguide device 13, and is configured to be optically coupled to the waveguide device 13 to enable exposure.

[0047] 5(a) and 5(b) are diagrams showing the general steps in a method for fabricating a structure, specifically a microstructure (or a microstructure), according to the present embodiment. The steps are described in a certain order. However, the order of the steps is not limited to the example shown in FIGS. 5(a) and 5(b). Apart from the general steps, a method for fabricating the structure will be described later with respect to some exemplary structures to be fabricated.

[0048] In the following description, the reference numerals already used will be used for ease of understanding. However, the method of fabricating the structure described below is not limited to the use of an exposure apparatus with a particular configuration, nor is it limited to the materials exemplified.

[0049] Referring to FIG. 5(a), a method 100a is shown.

[0050] The method 100a may include step S11. In step S11 (placement), the waveguide device 13, the mask device 15, and the photosensitive resin body 49 are placed in this order along the first axis ("rotation axis Rx"). The mask device 15 has a mask pattern 47 that defines light transmission. The waveguide device 13 includes a prism device 29, which has an incident surface 29b configured to receive light from the light source SC and an exit surface 29c configured to emit the received light. The incident surface 29b and the exit surface 29c of the prism device 29 are placed to form a prism structure. During placement in the exposure tool 11, a structural angle of the structure to be fabricated is specified. A total tilt angle that realizes this structural angle is specified in the exposure tool 11 used for fabrication. With respect to the angle of placement, the assignment of the total tilt angle to the prism angle of the prism device 29 and the tilt angle of the actuator 21 is specified. According to this specification, in the above arrangement, the total tilt angle is allocated to at least the prism angle of the prism device 29 and the tilt angle of the actuator 21 of the exposure apparatus 11. For example, one of the prism angle of the prism device 29 and the tilt angle of the actuator 21 is selected to match the other.

[0051] Specifically, the workpiece 35 is placed between the support table 27 and the mask device 15. In the exemplary workpiece 35, one surface of the workpiece 35 is in contact with the support table 27, and the other surface of the workpiece 35 is in contact with the mask device 15, as shown in FIG.

[0052] For example, the mask device 15, the workpiece 35, and the support base 27 can be surrounded by a refractive index matching material in the recess 18. The mask device 15 is arranged at a distance from the lid member 18g. The refractive index matching material fills the gap between the lid member 18g and the mask device 15 so that no air bubbles are present. When the housing structure 17 and the actuator 21 are tilted with respect to the array axis Arx (or the vertical axis), if air bubbles are present in the refractive index matching material, the air bubbles can gather at the upper end of the tilt depending on the viscosity of the refractive index matching material.

[0053] The second mask device 31 is selectively attached to the exposure tool 11. Alternatively, instead of providing the second mask device 31 in the exposure tool 11, the second mask pattern 43 can be provided on the exit surface 13c of the waveguide device 13, the exit surface 29c of the prism device 29, or the upper surface or inner surface of the lid member 18g.

[0054] Alternatively, the second mask device 31 can be provided with a second mask pattern 43 with a large aperture that passes all the light beams.

[0055] The method 100a may include step S12. In step S12 (exposure), a beam of light is irradiated onto the photosensitive resin body 49 from the mask device 15 through the exit surface 29c of the waveguide device 13 or the prism device 29 and the mask pattern 47 of the mask device 15. This irradiation is performed while rotating the photosensitive resin body 49 and the mask device 15 relative to the waveguide device 13 or the prism device 29 around a rotation axis Rx. The beam of light onto the photosensitive resin body 49 is defined by the mask pattern 47 of the mask device 15. The frequency of the rotation may be, for example, several Hertz.

[0056] For example, in the exposure, a refractive index matching material can be provided between the exit surface 29c of the prism device 29 and the mask device 15. Specifically, the photosensitive resin body 49 is immersed in the refractive index matching material (for example, liquid or gel) filled in the recess 18. Irradiating the photosensitive resin body 49 through the refractive index matching material can increase the variable range of the incident angle with respect to the light incident surface 15b of the mask device 15 while avoiding light reflection on the light incident surface of the mask device 15. The mask device 15 has a light exit surface 15c on the opposite side of the light incident surface 15b.

[0057] In order to irradiate the photosensitive resin body 49 with a light beam, the light for exposure can be irradiated onto the incident surface 29b of the prism device 29 from an angle inclined with respect to the normal to the incident surface 29b. The light source SC is oriented with respect to the incident surface 29b of the prism device 29. During exposure in the exposure apparatus 11, a total tilt angle that realizes this structural angle is specified in the exposure apparatus 11 based on a structural angle specified for the structure to be fabricated. With respect to the exposure angle, the allocation of the orientation angle of the light source SC, excluding the prism angle of the prism device 29, and the tilt angle of the actuator 21 is adjusted. According to this adjustment, the total tilt angle is allocated to the orientation angle of the light source SC, the prism angle of the prism device 29, and the tilt angle of the actuator 21 of the exposure apparatus 11 during the above exposure.

[0058] The photosensitive resin body 49 and the mask device 15 in close contact with the photosensitive resin body 49 rotate relative to the prism device 29 within the refractive index matching material.

[0059] When the photosensitive resin body 49 is irradiated with the light beam, exposed resin is produced from the photosensitive resin body 49 .

[0060] The method 100a may include step S13. In step S13 (development), after irradiating the photosensitive resin body 49, the exposed resin is developed to generate a resin body. The resin body includes a photosensitive resin body that has been hardened by exposure and development.

[0061] The method 100a may include step S14. In step S14 (processing), the resin body may be processed after the exposed resin is developed.

[0062] Exemplary processing of the resin body includes, for example, peeling the resin body from the support 48, processing a portion of the resin body (e.g., a structure having a microstructure as a fine structure) to adjust the size of the resin body, treating the resin body with a liquid for the next step, and forming a coating film. After processing the resin body, the resin body can be used to make a product, which will be described in subsequent embodiments.

[0063] The method 100a may include step S15. In step S15 (processing), the support 48 is processed using the resin body as a mask. This processing includes at least one of wet etching and dry etching.

[0064] The method 100a may include step S16. In step S16 (peeling), the resin body is removed from the support 48 or the processed support 48. Removing the resin body includes, for example, immersing the mask as the resin body in a stripping solution.

[0065] Referring to FIG. 5(b), a method 100b is shown.

[0066] The method 100b may include step S21. In step S21 (arrangement), the waveguide device 13, the second mask device 31, the mask device 15, and the photosensitive resin body 49 are arranged in this order in the direction of the rotation axis Rx. The mask device 15 and the second mask device 31 have mask patterns that define light transmission.

[0067] The mask device 15 is disposed in the recess 18 and rotated by the actuator 21. The waveguide device 13 includes a prism device 29. The second mask device 31 has a second mask pattern 43 that defines light transmission. The second mask device 31 is disposed in the recess 39 and is spaced apart from the mask device 15 via a lid member 18g. Therefore, the second mask device 31 does not rotate. The structural angle of the structure to be fabricated is specified during placement in the exposure tool 11. The total tilt angle that realizes this structural angle is specified in the exposure tool 11 used for fabrication. The allocation of the total tilt angle to the prism angle of the prism device 29 and the tilt angle of the actuator 21 is specified with respect to the angle of placement. According to this specification, the total tilt angle is allocated to at least the prism angle of the prism device 29 and the tilt angle of the actuator 21 of the exposure tool 11 during the above placement. For example, one of the prism angle of the prism device 29 and the tilt angle of the actuator 21 is selected to match the other.

[0068] The second mask pattern 43 is not provided on the output surface 13c of the waveguide device 13 or the output surface 29c of the prism device 29. However, as described in the method 100a, the second mask pattern 43 can be provided on the output surface 13c of the waveguide device 13, the output surface 29c of the prism device 29, or the outer or inner surface of the cover member 18g. In this case, the exposure apparatus 11 is not provided with the second mask device 31.

[0069] The prism device 29 has an entrance surface 29b configured to receive light from the light source SC and an exit surface 29c configured to emit light. The exit surface 29c of the prism device 29 is optically coupled to the second mask device 31. The second mask device 31 is optically coupled to the mask device 15 via the lid member 18g. The mask device 15 is optically coupled to the photosensitive resin body 49.

[0070] The light source SC is oriented toward the incident surface 29b of the prism device 29. During exposure, based on a structure angle specified for the structure to be created, a total tilt angle that realizes this structure angle is specified in the exposure apparatus 11. With respect to the angle of exposure, the allocation of the orientation angle of the light source SC, excluding the prism angle of the prism device 29, and the tilt angle of the actuator 21 is adjusted. According to this adjustment, the total tilt angle is allocated to the orientation angle of the light source SC, the prism angle of the prism device 29, and the tilt angle of the actuator 21 of the exposure apparatus 11 during the above exposure.

[0071] The second mask device 31 can be disposed so as to contact either the exit surface 29c of the prism device 29 or the lid member 18g. In this arrangement, the refractive index matching material (liquid, solid, or gel) in the recess 39 is provided between the second mask device 31 and the exit surface 29c of the prism device 29, or between the second mask device 31 and the lid member 18g.

[0072] Alternatively, the second mask device 31 can be disposed in the recess 39 at a distance from the exit surface 29c of the prism device 29 and the lid member 18g, and surrounded by the refractive index matching material in the recess 39.

[0073] The method 100b may include step S22. In step S22 (exposure), the photosensitive resin body 49 is irradiated with light beams from the second mask device 31 and the mask device 15 through the prism device 29, the second mask device 31, and the mask device 15 of the waveguide device 13. This irradiation is performed while rotating the photosensitive resin body 49 and the mask device 15 around the rotation axis Rx relative to the waveguide device 13 (prism device 29) and the second mask device 31. The light beams to the photosensitive resin body 49 are defined by the mask pattern 43 of the second mask device 31 and the mask pattern 47 of the mask device 15. The rotation frequency can be, for example, several Hertz.

[0074] For example, in the exposure, a refractive index matching material can be provided between the exit surface 29c of the prism device 29 and the mask device 15. Specifically, the photosensitive resin body 49 is immersed in the refractive index matching material (liquid) filled in the recess 18. When the photosensitive resin body 49 is irradiated through the refractive index matching material, the angle of incidence with respect to the light incident surface of the mask device 15 can be increased.

[0075] When the photosensitive resin body 49 is irradiated with the light beam, exposed resin is produced from the photosensitive resin body 49 .

[0076] The method 100b may include step S23. In step S23 (development), after irradiating the photosensitive resin body 49, the exposed resin is developed to generate a resin body, which includes a photosensitive resin body that has been hardened by exposure and development.

[0077] The method 100b may include step S24. In step S24 (processing), the resin body may be processed after the exposed resin is developed. An exemplary process may include forming a coating film.

[0078] The method 100b may include step S25. In step S25 (processing), after the exposed resin is developed, the support 48 is processed using the resin body as a mask. This processing includes at least one of wet etching and dry etching.

[0079] The method 100b may include step S26. In step S26 (peeling), after processing the support 48 using the resin body as a mask, the mask is removed from the processed support 48. Removing the mask includes, for example, immersing the resin body as a mask in a stripping solution.

[0080] The angle of incidence on the photosensitive resin body 49 in methods 100a and 100b is adjusted according to the angle to be provided to the structure to be fabricated. This angle adjustment can be achieved by at least one of the angle of incidence of light on the incident surface 29b of the prism device 29, the prism angle, and the angle of the support base 27. Exemplary angle adjustments can be adjusted by selecting the prism angle, by selecting both the prism angle and the tilt of the support base 27, or by adjusting the angle of incidence of light from the light source SC, the prism angle, and the tilt angle of the support base 27.

[0081] In methods 100a and 100b, when the waveguide device 13, the mask device 15 and the photosensitive resin body 49 are positioned, a second angle ANG2 and a third angle ANG3 can be specified so as to obtain a first angle ANG1 of irradiation onto the photosensitive resin body 49.

[0082] Specifically, when arranging the waveguide device 13, the mask device 15, and the photosensitive resin body 49, the second angle ANG2 can be specified, and then the prism device 29 can be selected to specify the third angle ANG3 so as to obtain the first angle ANG1 for irradiation onto the photosensitive resin body 49. Alternatively, when arranging the waveguide device 13, the mask device 15, and the photosensitive resin body 49, the prism device 29 can be selected to specify the third angle ANG3, and then the second angle ANG2 can be specified so as to obtain the first angle ANG1 for irradiation onto the photosensitive resin body 49.

[0083] In methods 100a and 100b, the resin body can include a microstructured mold configured to produce a retroreflective material, and the resin body can include a microstructured mold configured to produce a resin base for friction-based power generation.

[0084] In the methods 100a and 100b, the photosensitive resin body 49 can be formed on a support having a semiconductor surface (eg, a semiconductor substrate such as a semiconductor wafer).

[0085] In the methods 100a and 100b, the prism device 29 can be removable from the waveguide device 13 independently of the second mask device 31. After the prism device 29 is removed, the photosensitive resin body 49 can be irradiated with a light beam via the waveguide device 13 and the mask device 15. Also, after the prism device 29 is removed, the photosensitive resin body 49 can be irradiated with a light beam via the second mask device 31, the waveguide device 13, and the mask device 15.

[0086] 6 and 7 are diagrams showing the relationship between light flux and rotation when exposing a photosensitive resin body using two masks. FIGS. 8(a) and 8(b) are diagrams showing the structure after exposure and development through the masks of FIGS. 6 and 7, respectively. To simplify the explanation of exposure, the mask pattern 47 of the mask device 15 and the second mask pattern 43 of the second mask device 31 are simplified. The relationship between light flux and rotation when exposing a photosensitive resin body using a single mask can be understood from the following explanation, assuming that the second mask pattern 43 of the second mask device 31 is a full aperture. In FIGS. 6 and 7, air or a refractive index matching material can be provided between the prism device 29, the second mask device 31, and the mask device 15.

[0087] In Figure 6, the housing structure 17 of the exposure device 11 is tilted at an angle ANG2 in the direction of the arrow INCRI. This tilt can be adjusted by the fixing device 23. The solid line with the arrow represents the propagation of light. The angle of incidence on the photosensitive resin body 49 is related to the tilt of the support table 27 and the use of the prism device 29.

[0088] 6, the exemplary second mask pattern 43 has a so-called fan-shaped opening including two radial lines intersecting at the rotation axis (Rx) and two circular arcs intersecting these radial lines to close a region. The second mask device 31 is arranged so that these fan-shaped openings extend in the direction of the arrow INCRI. Also, the exemplary mask pattern 47 of the mask device 15 has a single circular opening located on the circumference at a certain distance (radius) from the rotation axis (Rx).

[0089] The photosensitive resin body 49 and the mask device 15 rotate together (arrow 28). As the mask device 15 rotates, the mask pattern 47 (single opening) repeatedly receives transmitted light from the first opening 43b and the second opening 43c (sector-shaped openings) of the fixed second mask pattern 43.

[0090] Specifically, in an arrangement where the transmitted light from the first opening 43b is irradiated at the position of the mask pattern 47 (single opening), this transmitted light forms a first exposure region RG1 tilted outward through the mask pattern 47 (single opening). In an arrangement where the mask device 15 is rotated 180 degrees (arrow 28b), the transmitted light from the second opening 43c forms a second exposure region RG2 tilted toward the rotation axis (Rx). In this arrangement, the first exposure region RG1 is oriented tilted outward and is not exposed.

[0091] As the photosensitive resin body 49 rotates, it is repeatedly exposed to light from the first opening 43b of the second mask pattern 43 and the mask pattern 47 (single opening), and the first exposed region RG1 accumulates an amount of exposure light. The growth of the first exposed region RG1 is associated with the first opening 43b of the second mask pattern 43, and the direction of growth of the first exposed region RG1 is associated with the angle of incidence of light on the photosensitive resin body 49.

[0092] Furthermore, the second exposure region RG2 accumulates an amount of exposure light by receiving light from the second opening 43c of the second mask pattern 43 and the mask pattern 47 (single opening). The growth of the second exposure region RG2 is associated with the second opening 43c of the second mask pattern 43, and the direction of growth of the second exposure region RG2 is associated with the angle of incidence of light on the photosensitive resin body 49.

[0093] When receiving light from the second opening 43c of the second mask pattern 43 and the mask pattern 47 (single opening), the first exposure region RG1 is rotated by 180 degrees as indicated by arrow 28c to be located at the base of the second exposure region RG2. Similarly, when receiving light from the first opening 43b of the second mask pattern 43 and the mask pattern 47 (single opening), the second exposure region RG2 also moves due to the rotation.

[0094] In this way, when the first exposure region RG1 and the second exposure region RG2 grow cumulatively, an exposure region such as that shown in Fig. 8(a) is formed. In Fig. 8(a), the first exposure region RG1 and the second exposure region RG2 are arranged along a reference plane REF1 (the radial direction of the rotation circle representing the rotation of the mask pattern) extending in the direction of the arrow INCRI. The reference plane REF1 is perpendicular to the reference plane REF2, which is a tangent plane to the circumferential direction of the rotation circle.

[0095] In Figure 7, the housing structure 17 of the exposure apparatus 11 is tilted at an angle ANG2 in the direction of the arrow INCRI. The solid line with the arrow represents the propagation of light. The illustration in Figure 7 differs from that in Figure 6 in that the axis is perpendicular to the arrow INCRI.

[0096] 7, the second mask pattern 43 of the second mask device 31 has so-called fan-shaped openings including two radial lines intersecting at the rotation axis (Rx) and four circular arcs intersecting these radial lines to close a region. The fan-shaped openings are away from the center of rotation of the second mask device 31, and the inner circular arcs are also away from the rotation axis (Rx). These fan-shaped openings are arranged along a direction that intersects with the direction of the arrow INCRI.

[0097] The mask pattern 47 of the mask device 15 has a single circular opening located at a certain distance (radius) from the axis of rotation (Rx).

[0098] The mask pattern 47 (single aperture) of the mask device 15 receives transmitted light from the third aperture 43d or the fourth aperture 43f of the second mask pattern 43 due to rotation.

[0099] The photosensitive resin body 49 and the mask device 15 rotate together. As the photosensitive resin body 49 rotates, it receives light from the third opening 43d of the second mask pattern 43 and the mask pattern 47 (single opening), and the third exposure region RG3 accumulates an exposure dose. The growth of the third exposure region RG3 is associated with the third opening 43d of the second mask pattern 43 and with the angle of incidence of the light on the photosensitive resin body 49.

[0100] When the mask device 15 is rotated 180 degrees (arrow 28g), the transmitted light from the fourth opening 43f forms a fourth exposure region RG4 tilted toward the rotation axis (Rx). The fourth exposure region RG4 receives light from the fourth opening 43f of the second mask pattern 43 and the single opening of the mask pattern 47, and accumulates an exposure dose. The growth of the fourth exposure region RG4 is related to the fourth opening 43f of the second mask pattern 43 and the angle of incidence of the light on the photosensitive resin body 49.

[0101] When receiving light from the fourth opening 43f of the second mask pattern 43 and the mask pattern 47 (single opening), the third exposure region RG3 is rotated by 180 degrees as indicated by arrow 28f to be located at the base of the fourth exposure region RG4. Similarly, when receiving light from the third opening 43d of the second mask pattern 43 and the mask pattern 47 (single opening), the fourth exposure region RG4 also moves by rotation.

[0102] In this way, as the third exposure region RG3 and the fourth exposure region RG4 grow cumulatively, an exposure region such as that shown in Fig. 8(b) is formed. In Fig. 8(b), the third exposure region RG3 and the fourth exposure region RG4 are arranged along a reference plane REF3 (the circumferential direction of the circle representing the rotation of the mask pattern) that extends in a direction intersecting the direction of the arrow INCRI. The reference plane REF3 is perpendicular to the reference plane REF4, and the reference plane REF4 extends in the radial direction of the rotation circle.

[0103] Next, a method for fabricating a structure by exposing a photosensitive resin body using a single mask will be described. An exemplary structure is a retroreflector.

[0104] In the two-mask exposure described with reference to Figures 6 and 7, the positions of the apertures (light-transmitting windows) in the fixed mask (fixed mask) define the range of angles (angles relative to the inclination arrow INCRI) at which light is provided to the rotating mask (rotating mask). The apertures (43b and 43c) in Figure 6 extend in the direction of the inclination arrow INCRI. The apertures (43d and 43f) in Figure 7 are positioned perpendicular to the inclination arrow INCRI. As a result of such exposure, the exposure methods using the fixed masks of Figures 6 and 7 can produce the structures shown in Figures 8(a) and 8(b), respectively.

[0105] According to the above description, it can be understood that when the mask pattern 47 (single opening) is changed from a circle to, for example, a rectangle, the exposure area is changed to a rectangle.

[0106] Furthermore, the first opening 43b, the second opening 43c, and the third opening 43d or the fourth opening 43f of the second mask pattern 43 can be provided in a single second mask device 31.

[0107] This exposure does not use the second mask device 31. When the opening size of the fixed mask is determined so as to irradiate the entire surface of the rotating mask, there is no light blocking by the mask pattern of the fixed mask.

[0108] Next, we explain how to expose a photosensitive resin using a single mask to create a structure, such as a mold with microstructures for a retroreflector.

[0109] FIG. 9 is a diagram showing the main steps in a method for making a mold having microstructures for a retroreflector according to this embodiment, and a method for making a retroreflector.

[0110] 9, a method 110 for making a retroreflector is shown. The method 110 can include the following exemplary steps:

[0111] The method 110 includes step S301. In step S301, a support 51 is prepared. The support 51 may include, for example, a glass substrate. After cleaning the support 51, the support 51 is subjected to a process of applying a primer 52 to a main surface 51b of the support 51 as a process for improving adhesion (e.g., an HMDS process or an OPA process).

[0112] The method 110 includes step S302. In step S302, a resist 53 is applied as a photosensitive resin body onto the support 51. The resist 53 may include a negative resist or a positive resist. An exemplary resist 53 may include SU-8 (negative resist). The thickness of the resist 53 varies depending on the mold to be fabricated.

[0113] The method 110 includes step S303. In step S303, a mask 54 is prepared as the mask device 15, and the prism device 29, the mask 54, and the resist 53 are arranged using the mask 54, and exposure (exposure of the resist 53) is performed using the prism device 29 according to the method shown in Figures 5(a) and 5(b). Note that the pattern surface of the mask 54 may face the resist 53.

[0114] An exemplary retroreflector mask 54 is shown in part (a) of Figure 10. Referring to part (a) of Figure 10, the mask 54 includes an equilateral triangular arrangement of geometric shapes. The equilateral triangular regions 54b are spaced apart by separation regions 54c. For exposure using a negative resist (e.g., SU-8), the exemplary retroreflector mask 54 includes a light-shielding film in the equilateral triangular regions 54b as a light-shielding portion, and openings in the light-shielding film in the separation regions 54c as a light-transmitting portion. The retroreflector mask 54 is not limited to an equilateral triangular arrangement, and may include an arrangement of other geometric shapes different from equilateral triangles.

[0115] The method 110 includes step S304, in which the exposed resist 53 is developed to form a resin body 55 disposed on the main surface 51b of the support 51.

[0116] Part (b) of Figure 10 shows an SEM image of a resin body 55 produced using an exemplary retroreflector mask 54. The array of equilateral triangular regions 54b is converted into repeatedly arranged depressions in the shape of triangular pyramids (pyramids with steep sides) by oblique exposure and development using the prism device 29. Part (c) of Figure 10 shows an enlargement of the SEM image shown in part (b) of Figure 10. These depressions are formed corresponding to the isolated regions 54c of the mask 54. The size of the array of depressions in the shape of triangular pyramids depends on the size of the equilateral triangles in the mask 54.

[0117] The growth of the exposed region will now be described. When a light beam is irradiated from the opening in the light shielding film of the isolation region 54c, the light is incident on the negative resist at an angle.

[0118] When the rotating mask (mask device 15) rotates so that one side of an equilateral triangle of the rotating mask extends perpendicular to the direction of the arrow INCRI in Fig. 6, the incident light exposes the resist to form a first side of a pyramid. Based on the analogy of the exposure in Fig. 6, the mask pattern (circular 47) in Fig. 6 is changed to a rectangle that extends perpendicular to the direction of the arrow INCRI and defines one side of the equilateral triangle.

[0119] The remaining two sides of the equilateral triangle of the rotating mask are exposed to resist to form the sides of adjacent pyramids.

[0120] When the rotation of the rotatable mask causes another side of the equilateral triangle of the rotatable mask to extend perpendicular to the direction of the arrow INCRI, light from the opening in the light-shielding film of the isolation region 54c enters the negative resist at an oblique angle. This incident light exposes the resist to form a second side different from the first side of the pyramid. In this arrangement, the remaining two sides of the equilateral triangle of the rotatable mask expose the resist to form the respective sides of the adjacent pyramid.

[0121] When the remaining side of the equilateral triangle of the rotatable mask extends in a direction perpendicular to the direction of the arrow INCRI during rotation of the rotatable mask, light is incident on the negative resist at an oblique angle from the opening in the light-shielding film of the isolation region 54c. This incident light exposes the resist to form a third side of the pyramid, separate from the first and second side. The remaining two sides of the equilateral triangle of the rotatable mask expose the resist to form the respective side surfaces of the adjacent pyramid.

[0122] 9, the method 110 includes step S305. In step S305, a film 56 (barrier coat) of a release agent is formed on the surface of the resin body 55 by, for example, coating.

[0123] The method 110 includes step S306, in which after applying a release agent, resin is poured onto the resin body 55 to form a molded resin body 57. The resin may include, for example, a silicone elastomer, and an exemplary silicone elastomer may include polydimethylsiloxane (PDMS).

[0124] The method 110 includes step S307. In step S307, the molded resin body 57 is removed from the resin body 55. The resin body 55 can be reused.

[0125] The molded resin body 57 includes an array of pyramidal protrusions (the protrusions have sloping sides that meet at an apex) and separation grooves (grid-like separation grooves) configured to define the array, the separation grooves having a width that provides a gap for sufficient separation of the protrusions to allow total internal reflection at adjacent protrusions.

[0126] The method 110 includes step S308. In step S308, a film 58 (barrier coat) of a release agent is formed on the surface of the molded resin body 57 by, for example, coating.

[0127] Method 110 includes step S309. In step S309, after applying a release agent, resin is poured onto molded resin body 57 to form a molded resin body 59 of the retroreflector. This resin may include, for example, a silicone elastomer, and an exemplary silicone elastomer may include a material such as polydimethylsiloxane (PDMS) (e.g., a material that can be releasably treated).

[0128] The method 110 includes step S310, in which the molded resin body 59 of the retroreflector is removed from the molded resin body 57. The molded resin body 57 can be reused.

[0129] Method 110 includes step S311. In step S311, after applying a release agent, a candy material, for example, is poured onto molded resin body 59, forming retroreflector 60. This candy material can include an edible material, for example, reduced euisomaltulose. Exemplary reduced euisomaltulose has a refractive index of 1.5266, while polydimethylsiloxane (PDMS) has a refractive index of 1.41. Specifically, the material of retroreflector 60 can have a refractive index greater than that of polydimethylsiloxane (PDMS). Additionally, retroreflector 60 can include an inedible material.

[0130] The method 110 includes step S312. In step S312, the retroreflector 60 is removed from the molded resin body 59 to obtain the retroreflector 60. The molded resin body 59 can be reused.

[0131] These steps complete the retroreflector 60. The steep-sided cone shape fabricated using the method shown in Figures 5(a) and 5(b) can provide retroreflector 60 with microstructured side slopes that facilitate total reflection. Retroreflector 60 can include candy material or polydimethylsiloxane (PDMS).

[0132] Figure 11(a) shows the relationship between the exposure dose for fabricating a retroreflector and the feature size of the fabricated retroreflector mold (measurement of the length of one side of a triangle in the developed resist). The exposure doses used were 200, 300, 400, 500, and 600 (mJ / cm). 2 ) from 200 to 600 (mJ / cm 2 ) the following can be understood from the exposure dose: A large exposure dose is preferable for forming narrow feature dimensions. A low exposure dose is preferable for forming wide feature dimensions. The support stage 27 of the exposure tool 11 is tilted at 36.6 degrees with respect to the horizontal plane. The prism angle of the prism device 29 is 45 degrees. The inclination angle of the incident light on the resist is 35.3 degrees for both the exposure tool 11 and the prism device 29. A negative resist is used for this production.

[0133] Also, 200 (mJ / cm 2 ) exposure allows for the formation of structures with a 50 μm structure dimension error within 1 μm.

[0134] Figure 11(b) shows the relationship between the structural spacing of the fabricated retroreflector mold and the pixel value in an image of the reflected light from the retroreflector captured by a camera. As the structural spacing decreases, the number of pixels increases, resulting in higher reflection intensity. This evaluation was performed using a molded resin body 57. The structural spacing of the microstructure of the fabricated retroreflector is defined as the distance between adjacent depressions (triangular pyramidal depressions). The structural spacing is, for example, the width of the protrusions in the developed resin body. In the following explanation, "pixel value" is defined as the reflection intensity of light. The height of the microstructure of the fabricated retroreflector is 43 μm.

[0135] The presence or absence of retroreflection is evaluated as follows: The camera and the reflective material that is a candidate for retroreflector are fixed in position. Light of the same intensity is irradiated onto the reflective material from the lighting, and the average pixel value of the structure that was confirmed to be retroreflecting from the reflective material (the reflective material that is a candidate for retroreflector) is calculated as the pixel value. The pixel value estimated in this way is used as the value on the vertical axis.

[0136] A retroreflector with a high pixel value exhibits a high reflection intensity, which is specifically produced by at least one of the following: a small structural spacing, steep angles between the apex and sidewalls of the retroreflector's pyramids, and a uniform arrangement of pyramids across the entire surface of the retroreflector.

[0137] Exemplary reflection intensities in Figure 11(b). Structural spacing (μm), average reflection intensity. 3, 57.48. 5, 138.04. 10, 100.28. 12, 92.21. 15, 76.60. 20, 73.10. 25, 63.61.

[0138] The minimum structure spacing depends on the resolution of the resist, and in this case, a negative resist (SU-8) was used. An exemplary minimum structure spacing is 3 μm or less and can be larger than the resolution limit of the resist. An exemplary minimum structure spacing can be 5 μm or less. An exemplary minimum structure spacing can be 10 μm or less. An exemplary minimum structure spacing can be 15 μm or less. An exemplary minimum structure spacing can be 20 μm or less. An exemplary minimum structure spacing can be 25 μm or less. An exemplary minimum structure spacing can be 30 μm or less. An exemplary minimum structure spacing can be 40 μm or less. An exemplary minimum structure spacing can be 50 μm or less. An exemplary minimum structure spacing can be 55 μm or less. Furthermore, an exemplary structure spacing can be 3 μm or more. The dimensional error (variation) of each structure spacing was 1 μm or less.

[0139] The pixel value in an exemplary microstructure can be 60 or greater. The pixel value in an exemplary microstructure can be 70 or greater. The pixel value in an exemplary microstructure can be 80 or greater. The pixel value in an exemplary microstructure can be 90 or greater. The pixel value in an exemplary microstructure can be 100 or greater. The pixel value in an exemplary microstructure can be 110 or greater. The pixel value in an exemplary microstructure can be 120 or greater. The pixel value in an exemplary microstructure can be 125 or greater. The pixel value represents the grayscale value (brightness value) of one pixel (one pixel) in an image captured by a camera, and represents, for example, a gradation from 0 to 255.

[0140] Next, we explain how to expose a photosensitive resin body using a single mask to create a structure, such as a microstructure mold for an electrode base for frictional power generation.

[0141] FIG. 12 is a diagram showing the main steps in a method for fabricating a microstructured mold for an electrode base, a microstructured electrode base, and an electrode according to this embodiment.

[0142] 12, a method 120 for fabricating an electrode base and an electrode is shown. The method 120 can include the following exemplary steps:

[0143] The method 120 includes step S401. In step S401, a support 61 is prepared. The support 61 may include, for example, a glass substrate. After cleaning the support 61, the support 61 is subjected to a treatment of applying a primer 62 to the main surface 61b of the support 61 in order to improve adhesion of the main surface 61b of the support 61 (for example, an HMDS treatment or an OPA treatment).

[0144] The method 120 includes step S402. In step S402, a resist is applied as a photosensitive resin body on the support 61 to form a resist film 63. The resist film 63 may include a negative resist or a positive resist. An exemplary resist film 63 may include SU-8 (negative resist). The thickness of the resist film 63 varies depending on the structure to be fabricated.

[0145] The method 120 includes step S403. In step S403, a mask 64 is prepared as the mask device 15, and the prism device 29, the mask 64, and the resist film 63 are arranged and exposure (exposure of the resist film 63) using the prism device 29 is performed using the mask 64 in the manner shown in FIGS. 5(a) and 5(b).

[0146] An exemplary microstructure electrode-based mask 64 is shown in part (a) of Figure 13. Referring to part (a) of Figure 13, the mask 64 includes a two-dimensional array of quadrilaterals. The array of quadrilateral regions 64b is spaced apart by isolation regions 64c. For exposure using a negative resist (e.g., SU-8), the exemplary electrode-based mask 64 includes a light-shielding film in the quadrilateral regions 64b and has openings in the light-shielding film in the isolation regions 64c. The mask 64 is not limited to an array of quadrilaterals and may include an array of other geometric shapes different from quadrilaterals.

[0147] From the openings in the light-shielding film of the separation region 64c, light beams are incident on the negative resist at an inclination angle set by the exposure device 11. An array of pyramidal depressions is formed. This array is defined by the separation wall.

[0148] During rotation of the rotating mask, a pair of opposing sides of a rectangle in the rotating mask is defined by periodic openings (openings in the light-shielding film) located in the isolation region 64c. When these openings extend in a direction perpendicular to the direction of the arrow INCRI in FIG. 6, light beams from the openings in the isolation region 64c are incident on the negative resist at an inclination angle determined by the exposure of the exposure device 11. This incident light exposes the resist to form first inclined side surfaces of individual pyramidal depressions. Based on the analogy of the exposure in FIG. 6, the shape of the mask pattern (circular 47) in FIG. 6 is changed to a rectangular opening extending perpendicular to the direction of the arrow INCRI and defining one side of the rectangle.

[0149] The remaining pair of opposing sides of the rectangle of the rotating mask extends in the direction of the arrows INCRI in FIG. 6. The remaining pair of sides is defined by periodic openings located in the isolation region 64c. Light beams from these openings expose the resist to form isolation walls (isolation walls extending in the direction of the arrows INCRI) that define an array of pyramidal depressions. Based on the analogy of the exposure in FIG. 7, the shape of the mask pattern (circular 47) in FIG. 7 is changed to a rectangular opening that extends in the direction of the arrows INCRI and defines one side of the rectangle.

[0150] When the rotatable mask is rotated 90 degrees, the other pair of sides of the rotatable mask rectangle extends in a direction perpendicular to the direction of the arrow INCRI. At this time, the light beams from the openings of the isolation region 64c are incident on the negative resist at an inclination angle determined by the exposure. The incident light from the openings of the other pair of sides exposes the resist to form second inclined side surfaces adjacent to the first inclined side surfaces of each pyramidal depression. In addition, the light beams from the openings defining the original pair of opposing sides of the rotatable mask rectangle expose the resist to form separation walls (separation walls extending in the direction of the arrow INCRI).

[0151] When the rotatable mask is rotated another 90 degrees, the original pair of sides of the above-mentioned rectangle of the rotatable mask extends in a direction perpendicular to the direction of the arrow INCRI. At this time, the light beams from the openings of the isolation region 64c are incident on the negative resist at an inclination angle determined by the exposure. The incident light from the openings of the original pair of sides exposes the resist to form a third inclined side (an inclined side opposite the first inclined side) adjacent to the second inclined side of each pyramidal depression. The light beams from the openings defining another pair of opposing sides of the rectangle of the rotatable mask expose the resist to form a separation wall (a separation wall extending in the direction of the arrow INCRI).

[0152] When the rotatable mask is rotated another 90 degrees, another pair of sides of the above-mentioned rectangle of the rotatable mask extends in a direction perpendicular to the direction of the arrow INCRI. At this time, the light beams from the openings of the isolation region 64c are incident on the negative resist at an inclination angle determined by the exposure. The incident light from the openings of the other pair of sides exposes the resist to form a fourth inclined side surface (an inclined side surface opposite the second inclined side surface) adjacent to the third inclined side surface of each pyramidal depression. In addition, the light beams from the openings defining the original pair of opposing sides of the rectangle of the rotatable mask expose the resist to form a separation wall (a separation wall extending in the direction of the arrow INCRI).

[0153] Returning to FIG. 12 , the method 120 includes step S404. In step S404, the exposed resist film 63 is developed to form a resin body 65 disposed on the main surface 61b of the support 61. The unexposed portions of the photosensitive resin body disappear, forming the resin body 65 having an array of depressions in the shape of truncated pyramids. The thickness and exposure time of the resist film 63 are adjusted to accommodate the shape of the truncated pyramids. Exemplary depression holes in the shape of truncated pyramids reach the main surface 61b of the support 61. The depression holes have side surfaces of the resin body 65 and a bottom surface made up of a portion of the main surface 61b of the support 61. The angle between the four sloping side surfaces of the depression and the bottom surface of the depression hole (the main surface 61b of the support 61) is less susceptible to variations in exposure dose and development associated with these variations.

[0154] The method 120 includes step S405. In step S405, a film 66 of a release agent is formed on the surface of the resin body 65 by, for example, coating (barrier coat).

[0155] Method 120 includes step S406. In step S406, after applying a release agent, a polymer material is poured onto resin body 65 to form molded resin body 67. This polymer material may include a rubber material such as silicone rubber. Exemplary silicone rubbers may include ecoflex™, silpot, or other silicone rubbers. Furthermore, molded resin body 67 is not limited to silicone rubber and may be made of a curable gel material such as a photo-curable ionic gel.

[0156] The method 120 includes step S407. In step S407, the molded resin body 67 is removed from the resin body 55. The resin body 65 and the support body 61 can be reused.

[0157] The molded resin body 67 includes an array of protrusions such as truncated pyramids (the protrusions have a flat upper surface and an inclined side surface) and separation grooves (lattice-like separation grooves) configured to define the array. The separation grooves have a width and a bottom surface, which enable adjacent protrusions to have sufficient space for deformation while improving the density of the protrusions.

[0158] Parts (b), (c), and (d) of Figure 13 show SEM images of molded resin bodies for electrode bases fabricated using the exemplary mask 64. Parts (b), (c), and (d) of Figure 13 show lateral truncated pyramids with different tilt angles (10 degrees, 20 degrees, and 30 degrees). These tilt angles of the truncated pyramids are related to the tilt angles of the exposures shown in Figures 5(a) and 5(b). The tilt angles of the truncated pyramids (10 degrees, 20 degrees, and 30 degrees) are formed by the tilt angles of the exposures (16.9 degrees, 34.8 degrees, and 56.6 degrees), respectively.

[0159] The method 120 includes step S408, in which the molded resin body 67 is processed to form the electrode base 68.

[0160] The method 120 includes step S409. In step S409, another insulating substrate 69 is prepared, and an electrode film 70 is formed on a main surface 69a of the substrate 69 to form a support base 71. The electrode film 70 can include, for example, a chromium film.

[0161] The method 120 includes step S410, in which the electrode base 68 is mounted on the support base 71.

[0162] These steps complete the microstructured electrode base and the microstructured electrode for frictional power generation.

[0163] FIG. 14 is a diagram showing a schematic diagram of a system for measuring the power generation characteristics of a friction power generation device.

[0164] 14(a), the system 80 includes a power generation device 80a and an electrical measurement device 80e. The power generation device 80a includes an upper electrode body 80b, a lower electrode body 80c, and a support 80s. The support 80s movably supports the upper electrode body 80b and the lower electrode body 80c. The upper electrode body 80b and the lower electrode body 80c have upper charged surfaces 80chgt and lower charged surfaces 80chgb, respectively.

[0165] The system 80 includes a drive mechanism 80d that enables repeated movement of the lower electrode assembly 80c in the direction of arrow MV.

[0166] The upper electrode body 80b includes an upper stage 81, a metal electrode 82, and a charged material 83 (e.g., a dielectric). The lower electrode body 80c includes a lower stage 85 and a metal electrode 87 that functions as a charged material and an electrode. The system 80 includes a gap adjustment device 80g for changing the maximum separation distance between the upper electrode body 80b and the lower electrode body 80c. In the present system 80, the load can be changed by adjusting the distance (gap) between the upper electrode body 80b and the lower electrode body 80c.

[0167] Additionally, the lower electrode body 80c of the present invention may include a load transducer 86 (eg, a load cell) that converts an applied load (force) into an electrical signal for measuring characteristics.

[0168] The electrical measuring device 80e includes a load 89b and a voltmeter 89c connected between the metal electrode 82 and the metal electrode 87.

[0169] In evaluating the power generation characteristics of the power generation device 80a, charged materials 83 of various shapes were attached and the power generation characteristics of each were measured. The following charged materials 83 were evaluated. Specifically, the charged materials 83 had a flat structure as well as various milli- and micro-structures.

[0170] Reference name, height, structure size, angle, number of structures, surface area ratio. (μm), (μm), (degrees), (counts), (dimensionless). Flat, None, None, None, None, 1.00. m10, 1500, 1058.0, 10, 196, 2.99. m20, 1500, 2183.8, 20, 49, 1.80. m30, 1500, 3464.1, 30, 16, 1.41. μ10, 100, 70.5, 10, 44521, 2.99. μ20, 100, 145.6, 20, 10404, 1.80. μ30, 100, 230.9, 30, 4096, 1.41.

[0171] The structure size in the table above is defined as the length of one side of the rectangle at the base of the protrusion. The angle above is defined as the angle between a first reference plane perpendicular to the top surface of the microstructure protrusion and a second reference plane along the side of the protrusion.

[0172] The feature size of the microstructures for the electrode base can be less than 1000 μm. The feature size can be less than 900 μm. The feature size can be less than 800 μm. The feature size can be less than 700 μm. The feature size can be less than 600 μm. The feature size can be less than 500 μm. The feature size can be less than 400 μm. The feature size can be less than 300 μm. The feature size can be less than 250 μm. The feature size can be less than 230 μm. The feature size can be less than 200 μm. The feature size can be less than 150 μm. The feature size can be less than 100 μm. The feature size can be less than 70 μm.

[0173] An exemplary height of the microstructure can be 100 μm or less. The height of the microstructure can be 500 μm or more and can be 10 μm or less. The aspect ratio (height / width) that can be fabricated of the microstructure is determined, for example, by the resist used. For a negative resist such as SU-8, the resist material used in the experiment, the maximum aspect ratio is about 10. An exemplary aspect ratio can be, for example, 10 or less. An exemplary height of the microstructure can be 500 μm or less and can be 10 μm or more.

[0174] The angle of a microstructure protrusion (structural angle) is defined as the angle between the side surface of the protrusion and a vertical reference plane at the bottom of the side surface, where the vertical reference plane is perpendicular to a horizontal reference plane extending along the top surface of the protrusion and passes through the bottom of the side surface of the protrusion. Exemplary angles of a microstructure protrusion can be 80 degrees or less; the angle can be 70 degrees or less; the angle can be 60 degrees or less; the angle can be 50 degrees or less; the angle can be 40 degrees or less; the angle can be 30 degrees or less; the angle can be 20 degrees or less; the angle can be 15 degrees or less; the angle can be 10 degrees or less; or the angle can be 5 degrees or less.

[0175] Referring to part (b) of Figure 14, an exemplary characteristic diagram is shown. In this characteristic diagram, the horizontal axis represents time. The left vertical axis represents the voltage between the electrodes (output voltage of the power generation device), and the right vertical axis represents the output of the load cell. One cycle consisting of contact and separation of the upper electrode body 80b and the lower electrode body 80c lasts approximately 0.3 seconds. The maximum value of the output voltage (Vp) was measured as a steep waveform.

[0176] During the period when the input load has a positive value (t2 to t3), the upper electrode body 80b and the lower electrode body 80c are in contact, and during the period when the input load has a substantially zero value (t1 to t2 and t3 to t4), the upper electrode body 80b and the lower electrode body 80c are spaced apart.

[0177] The generated power PW and the generated power GE of the waveform shown in part (b) of FIG. 14 are estimated by the following equations. PW=Vp 2 / Ropt. GE=Vp 2 / Ropt×△t. Ropt: Optimal load resistance, e.g. 2MΩ. Δt: Ratio of waveform duration to unit time (1 second) (calculated, for example, by integration).

[0178] 15 is a diagram showing a schematic diagram of a frictional power generation device using micro-structured electrodes. The main part of the power generation device 73 includes a first electrode 75 and a second electrode 77. The first electrode 75 and the second electrode 77 are movable relative to each other, and repeat the following operation. Contact between the first electrode 75 and the second electrode 77 (part (a) of FIG. 15). The first electrode 75 and the second electrode 77 move apart (part (b) of FIG. 15). The first electrode 75 and the second electrode 77 are spaced apart (part (c) of FIG. 15). The first electrode 75 and the second electrode 77 move closer to each other (part (d) of FIG. 15).

[0179] The first electrode 75 includes a resin body 75b that forms the surface of the first electrode 75 and a metal body 75c that supports the resin body 75b. The second electrode 77 includes a resin body 77b that forms the surface of the second electrode 77 and a metal body 77c that supports the resin body 77b. At least one of the surface of the resin body 75b of the first electrode 75 and the surface of the resin body 77b of the second electrode 77 can be provided with a microstructure for use as an electrode for frictional power generation.

[0180] The main part of the power generation device 73 can include at least one of a resin body 75b and a resin body 77b as a dielectric that separates the metal body 75c from the metal body 77c. Therefore, at least one of the surface of the resin body 75b of the first electrode 75 and the surface of the resin body 77b of the second electrode 77 can include a dielectric as a charged body.

[0181] Referring to part (a) of FIG. 15 , the first electrode 75 and the second electrode 77 are in contact with each other. Specifically, the contact between the resin bodies 75b and 77b causes the micro-interface structure to be crushed, resulting in friction. This friction polarizes the electric charge, and the charge accumulates as electrons in either the charged body (e.g., the resin body 75b) or the charged body (e.g., the resin body 77b), depending on the chargeability of the resin bodies 75b and 77b. As a result of this polarization, one surface of the first electrode 75 and the second electrode 77 becomes negatively charged, and the other surface becomes positively charged.

[0182] The resin body 75b and the resin body 77b are electrically isolated regions that are not connected to the outside. Therefore, the charge in these regions is conserved, and the amount of charge generated by friction is the net amount of charge.

[0183] The surface (referred to as "charged surface 75d") of resin body 75b of first electrode 75 is charged. Because resin body 75b is located between charged surface 75d and metal body 75c, they form a capacitor (C75) within first electrode 75. Therefore, in response to the charging of charged surface 75d, the interface between resin body 75b and metal body 75c also becomes charged.

[0184] The surface (referred to as "charged surface 77d") of resin body 77b of second electrode 77 is charged. Because resin body 77b is located between charged surface 77d and metal body 77c, they form a capacitor (C77) within second electrode 77. Therefore, in response to the charging of charged surface 77d, the interface between resin body 77b and metal body 77c also becomes charged.

[0185] The first electrode 75 and the second electrode 77 connected via a load are modeled as two capacitors (C75 and C77) connected in parallel, with the interface between the resin body 75b and the resin body 77b as the shared electrode. The shared electrode stores the same amount of positive and negative charges as accumulated charges.

[0186] In response to the charging of the charged surface 77d, the interface between the resin body 77b and the metal body 77c also becomes charged, while when the metal body 75c and the metal body 77c are connected via the load 76, the metal body 75c and the metal body 77c eventually become at the same potential.

[0187] Referring to part (b) of FIG. 15, the first electrode 75 and the second electrode 77 are separated by the movement indicated by the arrow MV1. During this separation, the original shape of the microstructure is restored. Furthermore, due to this separation, the charged surface 75d and the charged surface 77d are also separated, forming an intermediate capacitor (C0) in addition to the two capacitors (C75 and C77). The intermediate capacitor (C0) has the charged surface 75d and the charged surface 77d as its two electrodes, with air between them as a dielectric. A series connection of three capacitors (C75, C0, and C77) is formed. While the stored charge of the intermediate capacitor (C0) remains unchanged, the distance between the charged surface 75d and the charged surface 77d increases in accordance with the separation. Accordingly, the capacitance of the intermediate capacitor (C0) decreases, while the voltage across the terminals of the intermediate capacitor (C0) increases. Upon separation, the capacitances of the two capacitors (C75 and C77) may change according to the change in the area of ​​the charged surface due to the restoration of the micro-interface structure. Similarly, the capacitance of the middle capacitor (C0) may change due to the restoration of the micro-interface structure.

[0188] During the movement, the stored charge on the two capacitors (C75 and C77) increases.

[0189] Referring to part (c) of FIG. 15, as a result of the movement indicated by the arrow MV1, the first electrode 75 and the second electrode 77 are moved to the farthest position.

[0190] Referring to part (d) of FIG. 15, the first electrode 75 and the second electrode 77 are brought closer together by the movement indicated by the arrow MV2.

[0191] During the movement, the stored charge on the two capacitors (C75 and C77) decreases.

[0192] 16 is a diagram schematically illustrating deformation of a protrusion in a microstructure made of a flexible material such as a rubber material, such as silicone rubber. In FIG. 16, a single protrusion is depicted to facilitate understanding of the deformation. Furthermore, the microstructure is not limited to silicone rubber, and can be made of a curable gel material, such as a photocurable ionic gel.

[0193] The power generated by frictional power generation is proportional to the square of the charged area. The charged area refers to the area of ​​two charged bodies that remains charged after they come into contact and are separated. Microstructured electrodes contribute to increasing the charged area. Flexible microstructures also contribute to increasing the charged area.

[0194] 16(a), two electrodes (75, 77) are spaced apart. A charged surface 75d of the resin body 75b is spaced apart from a charged surface 77d of the protrusion of the resin body 77b. The protrusion has a flat upper end surface and can have various three-dimensional geometric shapes with a flat upper end surface, such as a pyramid shape with a flat upper end surface, or a truncated pyramid or truncated cone shape.

[0195] Referring to part (b) of Figure 16, the two electrodes (75, 77) are in contact with each other, and the resin body 75b and the resin body 77b are not significantly deformed.

[0196] 16(c), resin bodies 75b and 77b are significantly deformed after the two electrodes (75, 77) come into contact with each other. The deformation of resin bodies 75b and 77b increases the charging area, for example, the area of ​​at least one of charged surfaces 75d and 77d.

[0197] FIG. 17 shows an output waveform of a typical power generator for a typical charged member 83. Part (a) of FIG. 17 shows an exemplary generated power waveform of a power generator including an upper electrode body 80b including an electrode structure (μ10). The maximum generated power Wp was 0.900 μJ. Part (b) of FIG. 17 shows an exemplary generated power waveform of a power generator including an upper electrode body 80b including an electrode structure (m10). The maximum generated power Wp was 0.547 μJ. Part (c) of FIG. 17 shows an exemplary generated power waveform of a power generator including an upper electrode body 80b including an electrode structure (flat). The maximum generated power Wp was 0.116 μJ.

[0198] Comparing the exemplary power generation waveforms in parts (a), (b), and (c) of Figure 17 in terms of maximum power generation Wp, the maximum power generation Wp of the millimeter structure is lower than that of the flat type. The maximum power generation Wp of the micro structure is higher than that of the millimeter structure.

[0199] Part (d) of Figure 17 shows the relationship between the input load and the amount of power generated. In terms of power generation, the millimeter-structured electrodes are superior to the flat electrodes. Also, the micro-structured electrodes are superior to the millimeter-structured electrodes.

[0200] The flexible interface structure of the microstructure deforms in response to the application of a load. This deformation increases the contact area at the contact interface, which increases the maximum power generated in one cycle.

[0201] Furthermore, the deformation of the interface structure of the microstructure can increase the amount of deformation from the start of compression to the end of compression and from the start of expansion to the end of expansion, which increases the amount of power generated per cycle.

[0202] The microstructured charged surface improves power generation performance at low input loads. Specifically, the amount of power generated at an input load of 1 Newton (N) is about twice as high for a microstructured charged surface as for a millistructured charged surface. Furthermore, the maximum power generation is about four times as high for a microstructured charged surface as for a millistructured charged surface.

[0203] While exemplary generated power waveforms are shown in parts (a), (b), and (c) of FIG. 17, it can be seen from these drawings that the generated power waveform can be controlled by changing the structural angle. Specifically, compared to the waveforms in parts (a) and (b) of FIG. 17, the waveform in part (c) of FIG. 17 exhibits sharper peaks. The peak waveforms in parts (a) and (b) of FIG. 17 exhibit gentler rises and falls than the peak waveform in part (c) of FIG. 17. This indicates that the microstructure is effective in adjusting the generated power waveform. Specifically, controlling the generated power waveform allows, for example, efficient power rectification and power recovery. Controlling the generated power waveform can be performed to match the operating characteristics of the electrical circuit used in the power generation device, for example, a circuit realized by an integrated circuit.

[0204] FIG. 18 is a diagram showing the relationship between the angle of the actuator during exposure to fabricate a microstructure and the structure angle of the microstructure (the angle related to the tilt angle of the incident light during exposure) fabricated using the actuator angle. The horizontal axis represents the tilt angle of the actuator of the exposure device. The vertical axis represents the structure angle. The fabricated microstructure can be applied to, for example, retroreflectors and electrode bases. FIG. 18 also shows the structure angle of the microstructure in prism-assisted 3D lithography (PA) and 3D lithography (NP). In the exemplary prism-assisted 3D lithography (NP), a prism with a 45-degree prism angle was used. For the prism-assisted 3D lithography (NP), the structure angle at zero degrees on the horizontal axis (referred to as the "reference angle") varies depending on the prism angle used for exposure. Because the prism angle is greater than zero degrees, the reference angle of the graph of the prism PA in FIG. 18 can be changed over a wide range depending on the prism angle used for exposure.

[0205] Exposure PA utilizes the prism angle and the tilt angle of the actuator of the exposure tool 11, while exposure NP without a prism utilizes the tilt angle of the actuator of the exposure tool 11. In Fig. 18, the structure angle is defined as the angle in the microstructure made from the photosensitive material exposed and developed according to the flow shown in Fig. 12. The angle of incidence of light from the light source SC to the mask device (including the prism device) in exposure PA is equal to the angle of incidence of light from the light source to the mask device (excluding the prism device) in exposure NP.

[0206] We focus on the linearity of the structural angle of the microstructures in exposure NP and exposure PA (specifically, the linearity with respect to the tilt angle during exposure). Referring to FIG. 18, the linearity of the structural angle characteristics of exposure PA is superior to the linearity of the structural angle of the microstructures in exposure NP. Specifically, as the tilt angle during exposure increases, the structural angle of the microstructures in exposure NP tends to saturate with respect to the increase in the tilt angle during exposure, rather than increasing linearly. This tendency indicates that exposure PA is superior in angle controllability of the structural angle in the angle range shown in FIG. 18, for example, 0 degrees or more or greater than 0 degrees (angle range exceeding 60 degrees), for example, 70 degrees or less.

[0207] As can be seen from the graph in Figure 18, the difference in linearity is visually clear, especially in the angle range where the structural angle on the vertical axis exceeds 30 degrees. The use of a prism allows for excellent angle control.

[0208] Furthermore, the characteristics of the exposure PA exhibit a slight curvature that is strictly convex upwards. This curvature provides an angular region that is less sensitive to slight misalignments in the angle of the actuator 21. This region is mapped to the structure angle (angle range on the vertical axis) to be manufactured depending on the selection of the prism angle.

[0209] 5(a) and 5(b), when arranging the devices in the exposure apparatus 11, two angles, specifically the prism angle of the prism device 29 and the tilt angle of the actuator 21 of the exposure apparatus 11, are specified with respect to the exposure angle, and part or all of the total tilt angle is allocated to these angles. According to this specification, the total tilt angle is allocated to, for example, the prism angle of the prism device 29 and the tilt angle of the actuator 21 of the exposure apparatus 11 when arranging the devices in the exposure apparatus 11. Specifically, arranging the waveguide device 13, the mask device 15, and the photosensitive resin body 49 includes specifying the second angle ANG2 and the third angle ANG3 so that a first angle ANG1 of light irradiation to the photosensitive resin body 49 is obtained.

[0210] As described above, according to the present embodiment, it is possible to provide a method for fabricating a structure that can widen the angle of light incidence for exposure. Furthermore, according to the present embodiment, the method for fabricating a structure can exhibit excellent angle controllability with respect to the structural angle of the microstructure.

[0211] As will be understood from the above description, the present embodiment may have various aspects, which will be exemplified below.

[0212] A method for fabricating a structure according to a first aspect of this embodiment includes arranging a waveguide device, a mask device, and a photosensitive resin body in the direction of a first axis, wherein the mask device has a mask pattern that defines light transmission, and the waveguide device includes a prism device, the prism device having an incident surface configured to receive light from a light source and an exit surface configured to emit the light, the incident surface and the exit surface of the prism device being arranged to form a prism structure; and irradiating the photosensitive resin body with a beam of light through the exit surface of the waveguide device and the mask pattern of the mask device, wherein the irradiation is performed while rotating the photosensitive resin body and the mask device relative to the waveguide device around the first axis, and irradiating the photosensitive resin body with the beam of light, wherein the irradiation to the photosensitive resin body is performed from a direction inclined at a first angle with respect to the first axis.

[0213] In the method relating to the second aspect according to the first aspect of this embodiment, the light source is oriented toward the incident surface of the prism device, and irradiating the photosensitive resin body with the light beam includes irradiating the light onto the incident surface from an angle inclined with respect to the normal to the incident surface of the prism device, and the photosensitive resin body and the mask device can be rotated relative to the prism device.

[0214] In the method relating to the third aspect according to the first or second aspect of this embodiment, irradiating the photosensitive resin body with the light beam may include irradiating the photosensitive resin body with the light beam via a refractive index matching material provided between the exit surface of the prism device and the mask device.

[0215] In the method relating to a fourth aspect according to any one of the first to third aspects of this embodiment, irradiating the photosensitive resin body with the light beam includes generating an exposed resin from the photosensitive resin body, and the method may further include developing the exposed resin after irradiating the photosensitive resin body to generate a resin body.

[0216] In the method according to the fifth aspect of the present embodiment, the resin body may include a microstructure mold configured to produce a retroreflective material.

[0217] In the method according to the sixth aspect in accordance with the fourth aspect of this embodiment, the resin body may include a microstructure mold having a microstructure for an electrode base for power generation in a friction power generation system.

[0218] In a method relating to a seventh aspect according to any one of the fourth to sixth aspects of this embodiment, the photosensitive resin body is provided on a support, and the method may further comprise processing the support using the resin body as a mask.

[0219] In the method according to the eighth aspect of the present embodiment, the support may have a semiconductor surface, and the photosensitive resin body may be formed on the surface of the support.

[0220] In the method according to a ninth aspect according to any one of the first to eighth aspects of this embodiment, the light flux to the photosensitive resin body can be defined by the mask pattern.

[0221] In a method according to a tenth aspect of the present embodiment, which is in accordance with any one of the first to ninth aspects, the waveguide device includes a second mask pattern, the second mask pattern is disposed on either the entrance surface or the exit surface of the prism device, the light beam directed to the photosensitive resin body is defined by the mask pattern and the second mask pattern, and the irradiation can be performed while rotating the mask device and the photosensitive resin body relative to the prism device and the light source.

[0222] In a method according to an eleventh aspect of this embodiment, which is in accordance with any one of the first to ninth aspects, the waveguide device includes a second mask device having a second mask pattern, the light beam to the photosensitive resin body is defined by the mask pattern and the second mask pattern, and the irradiation can be performed while rotating the mask device and the photosensitive resin body relative to the prism device and the light source.

[0223] In a method relating to a twelfth aspect according to any one of the first to eleventh aspects of this embodiment, the relative rotation is performed by a driver having the first axis as a rotation axis, the photosensitive resin body is placed on a support table rotated by the driver, the driver is tiltably supported by a fixing device, the driver and the fixing device are arranged in the direction of an array axis, and arranging the waveguide device, mask device, and photosensitive resin body in the direction of the first axis includes tilting the driver and the prism device using the fixing device so that the rotation axis is inclined at a second angle with respect to the array axis.

[0224] In a method according to a thirteenth aspect of this embodiment, which is one of the first to eleventh aspects, the relative rotation is performed by a driver having the first axis as a rotation axis, the photosensitive resin body is placed on a support table rotated by the driver, the driver is tiltably supported by a fixing device, the driver and the fixing device are arranged in the direction of an array axis, and arranging the waveguide device, mask device, and photosensitive resin body includes tilting the driver and the prism device using the fixing device so that the rotation axis is tilted at a second angle with respect to the array axis, and the prism device has a prism angle of a third angle, and arranging the waveguide device, mask device, and photosensitive resin body in the direction of the first axis includes specifying the second angle and the third angle so that the first angle of irradiation to the photosensitive resin body is obtained.

[0225] The exposure apparatus of a fourteenth aspect of this embodiment comprises a support structure configured to support a waveguide device including a prism device having an incident surface configured to receive light for exposure and an exit surface configured to emit light from the incident surface; a container structure configured to rotate the mask device and the photosensitive resin body relative to the waveguide device around a first axis and to accommodate the mask device and the photosensitive resin body; a driver configured to rotate the mask device and the photosensitive resin body within the container structure; and a light source configured to be optically coupled to the waveguide device to enable exposure, wherein at least one of the support structure and the light source is configured to be able to adjust the direction of incidence of the light relative to the normal to the incident surface of the prism device.

[0226] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and scope of the present invention, all of which are included in the technical concept of the present invention. [Explanation of symbols]

[0227] 11. Exposure equipment, 13···Waveguide devices, 13b...Incidence plane, 13c...Emission surface, 15. Mask device, 17···Housing structure, 18... depression, 18b...bottom plate, 18c...side wall, 18d...through hole, 18f...Top edge, 18g···Cover member, 18h...opening, 18j...exterior, 21...driver, 21b: Rotating shaft body, 23...Fixing device, 25... Support base, 27...support stand, 28···arrow, 29 Prism device, 29b...Incidence plane, 29c...Emission surface, 31... Mask device, 33 Guide structure, 35...workpiece, 37 Prism holder, 37b···Guide surface, 39. Recess, 41 Mask base, 43... mask pattern, 43b, 43c, 43d, 43f...Aperture, 45... Mask base, 47···Mask pattern, 48...Support, 49...photosensitive resin body, 71... Support base, 73. Power generating equipment, 75, 77... electrode, 75b, 77b...resin body, 75c, 77c...metal body, 75d, 77d....Charged surface, 80···system, 80a···Power generating equipment, 80b...upper electrode body, 80c...lower electrode body, 80chgb···Lower charged surface, 80chgt···Upper charged surface, 80d···Drive mechanism, 80e···Electrical measuring devices, 80g...gap adjustment device, 80s...Support, 81...Upper stage, 82...Metal electrode, 83....Charged material, 85···Lower stage, 86... Load converter, 87...Metal electrode, 87···Load, 89···Voltmeter, 100a, 100b, 110, 120...method, ANG1, ANG2, ANG3...Angle, Arx: array axis, Ax1: Base normal axis C0, C75, C77... Capacitors CS: coordinate system, FLx....Irradiation axis, INCRI···arrow, MV1, MV2... arrows, REF1, REF2, REF3, REF4...reference planes, RG1, RG2, RG3, RG4... exposure area, Rx: Rotation axis, Rx2...Axis, SC...Light source.

Claims

1. 1. A method of fabricating a structure, comprising: arranging a waveguide device, a mask device, and a photosensitive resin body in a direction of a first axis, the mask device having a mask pattern that defines light transmission, the waveguide device including a prism device, the prism device having an entrance surface configured to receive light from a light source and an exit surface configured to exit the light, the entrance surface and the exit surface of the prism device being arranged to form a prism structure; irradiating the photosensitive resin body with the light beam through an exit surface of the waveguide device and the mask pattern of the mask device, the irradiation being performed while rotating the photosensitive resin body and the mask device relative to the waveguide device around the first axis; Equipped with The method wherein the irradiation of the photosensitive resin body is performed from a direction inclined at a first angle relative to the first axis.

2. the light source is directed toward the entrance surface of the prism device; irradiating the photosensitive resin body with the light beam includes irradiating the light beam onto the incident surface of the prism device from a direction inclined with respect to a normal to the incident surface, the photosensitive resin body and the mask device are rotated relative to the prism device; 10. The method of claim 1.

3. irradiating the photosensitive resin body with the light beam includes irradiating the photosensitive resin body with the light beam via a refractive index matching material provided between the exit surface of the prism device and the mask device.

10. The method of claim 1.

4. irradiating the photosensitive resin body with the light beam includes generating an exposed resin from the photosensitive resin body; The method further comprises, after irradiating the photosensitive resin body, developing the exposed resin to produce a resin body.

10. The method of claim 1.

5. The resin body includes a microstructure mold configured to produce a retroreflective material.

5. The method of claim 4.

6. The resin body includes a microstructure mold having a microstructure for an electrode base for power generation by friction power generation.

5. The method of claim 4.

7. the photosensitive resin body is provided on a support, The method further includes processing the support using the resin body as a mask.

5. The method of claim 4.

8. the substrate has a semiconductor surface; The photosensitive resin body is formed on the surface of the support.

8. The method of claim 7.

9. the light beam to the photosensitive resin body is defined by the mask pattern; 10. The method of claim 1.

10. the waveguide device includes a second mask pattern, the second mask pattern being disposed on one of the entrance surface and the exit surface of the prism device; the light beam to the photosensitive resin body is defined by the mask pattern and the second mask pattern; the irradiation is performed while rotating the mask device and the photosensitive resin body relative to the prism device and the light source.

10. The method of claim 1.

11. the waveguide device includes a second mask device having a second mask pattern; the light beam to the photosensitive resin body is defined by the mask pattern and the second mask pattern; the irradiation is performed while rotating the mask device and the photosensitive resin body relative to the prism device and the light source.

10. The method of claim 1.

12. the relative rotation is performed by a driver having the first axis as a rotation axis; the photosensitive resin body is provided on a support table that is rotated by the driver; the driver is tiltably supported by a fixing device; the driver and the fixing device are arranged in the direction of an arrangement axis; and arranging the waveguide device, the mask device, and the photosensitive resin body in the direction of the first axis includes tilting the actuator and the prism device using the fixing device so that the rotation axis is tilted at a second angle with respect to the alignment axis.

10. The method of claim 1.

13. the relative rotation is performed by a driver having the first axis as a rotation axis; the photosensitive resin body is provided on a support table that is rotated by the driver; the driver is tiltably supported by a fixing device; the driver and the fixing device are arranged in the direction of an arrangement axis; and positioning the waveguide device, the mask device, and the photosensitive resin body includes tilting the actuator and the prism device using the fixing device so that the rotation axis is tilted at a second angle with respect to the alignment axis; the prism device has a prism angle of a third angle; and arranging the waveguide device, the mask device, and the photosensitive resin body in the direction of the first axis includes specifying the second angle and the third angle so as to obtain the first angle of irradiation to the photosensitive resin body.

10. The method of claim 1.

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