JP2019087678A - Functional substrate and method of manufacturing the same, and imprint mold - Google Patents

Abstract

To provide a functional substrate capable of exhibiting a desired function by a functional membrane that is provided on a plane substantially orthogonal to a predetermined plane and a method of manufacturing the same, and an imprint mold having the functional substrate.SOLUTION: A functional substrate includes a base material having a first surface and a second surface facing the first surface, and a projecting structural part projecting from a first surface side of the base material. The projecting structural part includes: an upper surface; a first side surface continuous to the periphery of the upper surface and extending downward along the thickness direction of the base material; a flat surface continuous to the lower edge of the first side surface; and a second side surface continuous to the periphery of the flat surface and extending in a direction toward the first surface. A first functional membrane is formed on the first side surface, and part including a lower edge part of the first functional membrane is located in the projecting structural part.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a functional substrate and a method of manufacturing the same, and an imprint mold produced using the functional substrate.

  The nanoimprint technology known as a microfabrication technology uses an imprint mold in which a micro unevenness pattern is formed on the surface of a substrate, and transfers the micro unevenness pattern to a workpiece to equalize the micro unevenness pattern. It is a pattern formation technique to transfer. In particular, with the further miniaturization of wiring patterns and the like in semiconductor devices, nanoimprint technology has attracted attention in the manufacturing process and the like.

  As an imprint mold generally used in the nanoimprint technology, for example, a mold provided with a base, a convex structure projecting from the surface of the base, and a fine concavo-convex pattern formed on the upper surface of the convex structure is known. ing. By using such an imprint mold, the fine asperity pattern of the imprint mold is brought into contact with the imprint resin as a workpiece supplied onto the transfer substrate, thereby filling the fine asperity pattern with the imprint resin. . Then, by curing the imprint resin in that state, a pattern structure formed by transferring the fine asperity pattern of the imprint mold is formed.

  If the supply amount of the imprint resin is insufficient, the fine asperity pattern is not sufficiently filled with the imprint resin, which causes a defect (unfilled defect) in the pattern structure. On the other hand, it is extremely difficult to control the supply amount of imprint resin with high accuracy. If an imprint resin in an amount sufficient to prevent the occurrence of unfilled defects is supplied to the transfer substrate, when the imprint resin is brought into contact with the imprint resin, an excess of in-out in the convex structure of the imprint mold is generated. The printing resin is pushed out and adheres to the side surface of the convex structure. The imprint resin protruding to the outside of the convex structure and attached to the side surface is cured simultaneously with the imprint resin filled in the fine asperity pattern. As a result, when the imprint mold is pulled away from the imprint resin, a large stress acts, which may cause damage to the imprint mold or the pattern structure. In addition, in the case of performing imprint processing by the so-called step-and-repeat method, it is necessary to separate the imprinted region so that it does not overlap with the cured imprint resin when it protrudes to the outside of the convex structure. The number of times the imprint process can be performed on the transfer substrate is limited.

  In order to solve such a problem, an imprint mold is conventionally known in which a functional layer such as a light shielding layer is provided in a region surrounding the outer periphery of a pattern region in which a fine concavo-convex pattern is formed (Patent Document 1 , 2).

Patent No. 4869263 JP, 2010-251601, A

  In the imprint mold described in Patent Document 1, a light shielding layer is provided in a non-pattern area surrounding the outer periphery of the pattern area. Thereby, light is not irradiated to the imprint resin (photocurable resin) which has spread out to the outer side of the pattern area, and it is possible to prevent the imprint resin from being cured. However, in Patent Document 1, although it is premised that the light irradiated to the imprint resin through the imprint mold travels parallel to the thickness direction of the imprint mold, the imprint is actually performed. There is a problem that the light traveling obliquely with respect to the thickness direction of the mold hardens the imprint resin which has been protruded to the outside of the pattern area. In this respect, in the imprint mold described in Patent Document 1, although the light shielding film is provided also on the side surface orthogonal to the pattern region, connection between the side surface and the non-pattern region surrounding the outer periphery of the pattern region and the side surface It is extremely difficult to form a light shielding film capable of providing sufficient light shielding performance by sputtering or the like on the portion. Therefore, in the imprint mold described in Patent Document 1, there is still a possibility that the imprint resin that has run out to the outside of the pattern area may be cured.

  In addition, in the imprint mold described in Patent Document 2, a material having a first side surface portion and a first step portion continuous with the outer edge of the pattern region, and having water repellency or oil repellency in the first side surface portion. A coating film is formed, and it is possible to suppress that the imprint resin which has run out from the pattern area at the time of the imprint processing adheres to the first side portion to contaminate the imprint mold. However, it is extremely difficult to form a film having a desired function (water repellent function or oil repellent function) on the first side surface portion orthogonal to the pattern region, as in the light shielding film in Patent Document 1 above. is there. Therefore, also in the imprint mold described in Patent Document 2, there is still a possibility that the imprint resin that has run out to the outside of the pattern area may adhere to the first side surface of the imprint mold.

  In view of the above problems, according to the present disclosure, a functional substrate on which a desired function can be exhibited by a functional film provided on a surface substantially orthogonal to a predetermined surface, a method of manufacturing the same, and the functionality It is an object to provide an imprint mold having a substrate.

  In order to solve the above problems, as an embodiment of the present disclosure, a base material having a first surface and a second surface opposite to the first surface, and a convex structure protruding from the first surface side of the base material The convex structure is continuous with the upper surface, the outer edge of the upper surface, and a first side surface extending downward along the thickness direction of the substrate, and the flat surface continuous with the lower end of the first side surface A first functional film is formed on the first side surface, the second side surface being continuous with the outer edge of the flat surface and extending in the direction toward the first surface; A functional substrate is provided in which a portion including the lower end portion of the functional film is located in the convex structure.

  The first functional film may be made of a material having resistance to an etching solution that can be applied to the substrate, and the substrate is made of a material transparent to energy rays of a predetermined wavelength. The first functional film may be made of a material having a light shielding performance to the energy ray, and the first functional film may be made of a chromium material, a molybdenum material or gold.

  The first side surface and the flat surface are continuous via a curved surface located between them, and the curved surface is a surface of the first functional film formed on the first side surface. A second functional film may be formed continuously at the position of.

  A third functional film that is continuous with the second functional film may be formed on the flat surface, and the length of the first side surface in the thickness direction of the base may be 0.2 μm to 2 μm. can do.

  According to an embodiment of the present disclosure, there is provided a first surface, a second surface opposite to the first surface, and a step of preparing a base material having a protruding portion protruding from the first surface, and an upper surface of the protruding portion. Forming the groove on the upper surface of the protrusion surrounding the outer periphery of the predetermined region to be included; filling the groove with the functional material; and physically including the predetermined region. Forming a hard mask pattern having a size larger than that of the region on the upper surface of the protrusion, and using the hard mask pattern as an etching mask, and wetting the upper surface of the protrusion to a predetermined depth using a predetermined etching solution And etching the upper surface of the protrusion so as to expose a part of the functional material filled in the groove, but not all of the functional material. The law is provided.

  The upper surface of the protrusion may be wet etched so that the lower end of the functional material filled in the groove is positioned in the substrate, and the material having resistance to the etching solution as the functional material The base material may be made of a material transparent to energy rays of a predetermined wavelength, and a material having a light shielding performance to the energy rays may be used as the functional material, The method may further include the step of forming a functional material film on the surface of the base surrounding the outer side of the groove, which appeared by wet etching the upper surface of the protrusion. The groove may be formed by etching the upper surface of the protrusion through the mask pattern having the opening corresponding to the groove. It may form the grooves by cutting with respect to the upper surface of the opening dimension of the groove can be at least 50nm.

  According to one embodiment of the present invention, there is provided an imprint mold comprising: the functional substrate; and a concavo-convex pattern formed in a pattern area set on an upper surface of the convex structure.

  According to the present disclosure, a functional substrate which can exhibit a desired function by a functional film provided on a surface substantially orthogonal to a predetermined surface, a method of manufacturing the same, and an in-process having the functional substrate A print mold can be provided.

FIG. 1 is a cut end view showing a schematic configuration of an aspect of an imprint mold according to an embodiment of the present disclosure. FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a portion A in the imprint mold shown in FIG. FIG. 3 is a partially enlarged cut end view showing a schematic configuration of a portion B in the imprint mold shown in FIG. FIG. 4 is a partially enlarged cut end view for explaining the operation of a comparative imprint mold for showing the operation and effect of the imprint mold according to an embodiment of the present disclosure. FIG. 5 is a partially enlarged cut end view for explaining the operation of the imprint mold according to an embodiment of the present disclosure. FIG. 6 is a top view showing a schematic configuration of an imprint mold according to an embodiment of the present disclosure. FIG. 7 is a process flow diagram showing each process of a method of manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 8 is a process flow diagram following FIG. 7, showing each process of the method of manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 9 is a process flow diagram following FIG. 8, showing each process of the method of manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 10 is a partially enlarged cut end view showing an initial stage of a wet etching process in a method of manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 11 is a partially enlarged cut end view showing a stage subsequent to FIG. 10 in the wet etching process in the method of manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 12 is a partially enlarged cut end view showing a stage subsequent to FIG. 11 in the wet etching process in the method of manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 13 is a process flowchart showing each process of an imprint method using an imprint mold according to an embodiment of the present disclosure in a cut end surface. FIG. 14 is an exploded cross-sectional view (FIG. 14A) and a cross-sectional view (FIG. 14B) showing a schematic configuration of an imprint mold according to another embodiment of the present disclosure. FIG. 15 is a cut end view showing a schematic configuration of an imprint mold substrate that can be used in a method of manufacturing an imprint mold according to another embodiment of the present disclosure.

Embodiments of the present disclosure will be described with reference to the drawings.
In the drawings, in order to facilitate understanding, the shapes, the scales, the dimensional ratios of the longitudinal and lateral dimensions, and the like of the respective parts may be shown by being changed or exaggerated from the real thing. The numerical range represented using "-" in this specification etc. means that it is the range which includes each of the numerical value described before and behind "-" as a lower limit and an upper limit. In the present specification and the like, terms such as "film", "sheet", "plate" and the like are not distinguished from each other based on difference in designation. For example, "plate" is a concept that also includes members that can be generally called "sheet" and "film".

[Imprint mold]
1 is a cut end view showing a schematic configuration of one aspect of the imprint mold according to the present embodiment, and FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a portion A in FIG. FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a portion B in FIG.

  As shown in FIGS. 1 to 3, the imprint mold 1 according to the present embodiment includes a first surface 2A and a base 2 having a second surface 2B facing the first surface 2A, and a first base 2. It has a convex structure 3 protruding from the surface 2A, a concavo-convex pattern 4 formed on the upper surface 31 of the convex structure 3, and a depression 5 formed on the second surface 2B side.

  The substrate 2 is generally used as a substrate for imprint molds, for example, quartz glass substrate, soda glass substrate, fluorite substrate, calcium fluoride substrate, magnesium fluoride substrate, barium borosilicate glass, aminoborosilicate glass , Glass substrates such as alkali-free glass substrates such as aluminosilicate glass, polycarbonate substrates, polypropylene substrates, polyethylene substrates, polymethyl methacrylate substrates, resin substrates such as polyethylene terephthalate substrates, and two or more substrates arbitrarily selected from these A transparent substrate or the like such as a laminated substrate formed by laminating In the present embodiment, “transparent” means capable of transmitting light of a wavelength that can cure the imprint resin, and means that the transmittance of light having a wavelength of 150 nm to 400 nm is 60% or more. Preferably 90% or more, and particularly preferably 95% or more.

  It does not specifically limit as planar view shape of the base material 2, For example, substantially rectangular shape, substantially circular shape, etc. are mentioned. When the substrate 2 is made of a quartz glass substrate generally used for optical imprinting, the shape of the substrate 2 in plan view is usually substantially rectangular.

  The size of the substrate 2 (the size in plan view) is not particularly limited, but when the substrate 2 is made of the quartz glass substrate, for example, the size of the substrate 2 is about 152 mm × 152 mm. . Moreover, the thickness of the base material 2 may be suitably set in the range of, for example, about 300 μm to 10 mm, in consideration of strength, handleability, and the like.

  The convex structure 3 protruding from the first surface 2A of the base 2 is provided substantially at the center of the base 2 in a plan view. The shape in plan view of the convex structure 3 may be, for example, a substantially rectangular shape, but is not limited thereto, and any shape such as a substantially polygonal shape such as a substantially octagon, a substantially circular shape, a substantially elliptical shape, etc. It may be shaped. The size of the convex structure portion 3 is appropriately set according to the product and the like manufactured through the imprinting process using the imprint mold 1 and is, for example, a substantially rectangular shape of 33 mm ± 1 μm × 26 mm ± 1 μm. The convex structure part 3 of can be mentioned.

  The protruding height of the convex structure 3 (the length along the thickness direction of the base 2 between the first surface 2A of the base 2 and the upper surface 31 of the convex structure 3) is the imprint mold according to the present embodiment. It is not particularly limited as long as 1 can serve the purpose of including the convex structure portion 3 and may be set to, for example, about 10 μm to 100 μm.

  The convex structure 3 is continuous with the upper surface 31 having the pattern area PA in which the concavo-convex pattern 4 is formed and the outer peripheral edge of the upper surface 31 and is substantially orthogonal to the upper surface 31 (substantially in the thickness direction of the base 2 And the flat surface 34 which is continuous with the curved surface 33 and which is substantially parallel to the upper surface 31; and the curved surface 33 which is continuous with the lower end of the first side surface 32; And a second side surface portion 35 continuous with the outer peripheral edge of the outer surface 34.

The length T ₃₂ of the first side surface portion 32 in the thickness direction of the base material 2 may be, for example, about 0.2 μm to 2 μm, and preferably about 0.5 μm to 1 μm. If the length T ₃₂ exceeds 2 μm, the etching process in the process of manufacturing the imprint mold 1 takes too much time, and the manufacturing cost of the imprint mold 1 may be significantly increased. The difference between the height positions of the upper surface 31 and the flat surface 34 along the thickness direction of the substrate 2 is unevenness on the imprint resin 101 on the transferred substrate 100 (see FIG. 13A) during the imprinting process. It may be set to such an extent that the flat surface 34 does not contact the transfer substrate 100 when the pattern 4 is pressed.

  The imprint mold 1 according to the present embodiment has a functional film 6 that covers the first side surface portion 32, the curved surface 33 and the flat surface 34. The functional film 6 covers the first functional film 61 covering the first side surface portion 32, the second functional film 62 covering the curved surface 33 and continuing in the middle of the first functional film 61, and the flat surface And a third functional film 63 continuous with the second functional film 62.

  Examples of functions that can be exhibited by the functional film 6 (first to third functional films 61 to 63) include a light shielding function, a light absorption (light absorption) function, a low reflection function, a water and oil repellent function, and the like. Be The functional film 6 exerts a light shielding function to block the energy rays (UV etc.) traveling in the direction inclined with respect to the thickness direction of the base material 2 of the imprint mold 1 and the energy rays (UV etc.) It is possible to prevent the irradiation of the imprint resin that has run out from the upper surface 31 (pattern area PA) of the convex structure 3 of the imprint mold 1 to the outside. In addition, the functional film 6 exerts a light absorption (absorptive light) function, whereby the imprint mold 1 is combined with an energy ray (UV etc.) that travels in a direction inclined with respect to the thickness direction of the substrate 2 of the imprint mold 1 Can absorb the reflected light that is partially reflected by the energy beam (such as UV) that has reached the substrate to be transferred, and the energy beam (such as UV) can be absorbed by the convex structure 3 of the imprint mold 1. It is possible to prevent the irradiation of the imprint resin, which has run out from the upper surface 31 (pattern area PA) of the above, again. Furthermore, because the functional film 6 exhibits a low reflection function, a part of the energy beam (UV etc.) that has passed through the imprint mold 1 and reached the transfer substrate is reflected by the transfer substrate, but the functional film 6, the reflection of the reflected light can be suppressed, and the curing of the imprint resin protruding outside from the upper surface 31 (pattern area PA) of the convex structure 3 of the imprint mold 1 can be prevented. Furthermore, the functional resin 6 exerts a water and oil repellent function, whereby the imprint resin protruding outside from the upper surface 31 (pattern area PA) of the convex structure 3 of the imprint mold 1 is applied to the imprint mold 1. It becomes difficult to adhere and it can prevent that the imprint mold 1 is contaminated.

  The first functional film 61 is provided on the first side surface portion 32 such that the lower end portion thereof is embedded in the base material 2 (convex structure portion 3) (see FIG. 3). As described later, the first to third functional films 63 can be formed by, for example, chemical vapor deposition (CVD) such as atmospheric pressure CVD, low pressure CVD, plasma CVD, etc .; vacuum deposition, ion plating The first side surface portion 32, the curved surface 33, and the flat surface 34 are formed by physical vapor deposition (PVD) or the like such as sputtering, but it is difficult to form uniformly on the curved surface 33. In particular, the film thickness of the portion of the second functional film 62 located in the vicinity of the first side surface portion 32 becomes relatively thin. Therefore, in the vicinity of the second functional film 62 provided on the curved surface 33, in particular in the vicinity of the portion continuing to the first functional film 61, the function by the second functional film 62 may not be sufficiently exhibited. .

  For example, the functional film 6 (first to third functional films 61 to 63) is a light shielding film having a light shielding function, and the imprint resin is irradiated with energy rays (UV etc.) through the imprint mold 1 In such a case, the energy beam (UV etc.) generally travels in a direction inclined with respect to the thickness direction of the imprint mold 1 and the energy rays UV1 and UV4 progressing in parallel with the thickness direction of the imprint mold 1 Energy beams UV2 and UV3 (see FIGS. 4 and 5).

  The energy beam UV1 passes through the upper surface 31 (pattern area PA) of the convex structure 3, but the energy beam UV2 is blocked by the first functional film 61, and the energy beam UV4 is blocked by the third functional film 63. (See Figures 4 and 5). On the other hand, when the lower end portion of the first functional film 61 is not embedded in the base material 2 (convex structure 3), the energy ray UV3 passes through the second functional film 62 (see FIG. 4). However, as in the present embodiment, the lower end portion of the first functional film 61 is embedded in the base 2 (convex structure 3), so that the energy ray UV3 becomes the base 2 (convex structure 3). The light is blocked by the lower end portion of the first functional film 61 embedded in the (see FIG. 5).

  In order to exhibit such an effect more effectively, the length of the embedded portion 611 of the first functional film 61 embedded in the base 2 (the convex structure 3) (the length of the base 2) The length along the thickness direction is the direction (base material 2) from the area facing the upper surface 31 (pattern area PA) of the convex structure 3 on the second surface 2B side of the base material 2 toward the second functional film 62 The energy beam (UV etc.) traveling in the direction inclined with respect to the thickness direction of the light source may be set to a light shield (see FIG. 5), for example, about 0.1 .mu.m to 1 .mu.m. If the length of the embedded portion 611 is less than 0.1 μm, the second functional film 62 is formed from a region facing the upper surface 31 (pattern area PA) of the convex structure 3 on the second surface 2B side of the base material 2 There is a possibility that the energy beam (UV etc.) traveling in the direction toward the direction may not be blocked sufficiently, and the inward protruding from the upper surface 31 (pattern area PA) of the convex structure 3 at the time of imprint processing using the imprint mold 1 There is a risk of curing the print resin. On the other hand, if the length of the embedded portion 611 exceeds 1 μm, the etching process in the manufacturing process of the imprint mold 1 takes too much time, and the manufacturing cost of the imprint mold 1 may be significantly increased. . In addition, when the length of the embedded portion 611 exceeds 1 μm, it takes too long to fill the embedded portion 611 with the material constituting the first functional film 61, or the unfilled of the material tends to occur. There is also a risk of The length of the embedded portion 611 can be measured, for example, from a cross section along the thickness direction of the imprint mold 1 using a scanning electron microscope (SEM) or the like.

  The film thickness of the functional film 6 may be any thickness as long as the desired function can be exhibited. For example, when the function exhibited by the functional film 6 is a light shielding function, it may be about 10 nm to 100 nm. And preferably about 15 nm to 80 nm. As described later, the lower limit of the film thickness of the first functional film 61 which can also function as an etching stopper in the manufacturing process of the imprint mold 1 may be about 50 nm, preferably about 100 nm. .

  As a material which comprises the functional film 6 (1st-3rd functional film 61-63), what is necessary is just to exhibit a desired function. For example, when the functional film 6 (first to third functional films 61 to 63) has a light shielding function, the material is a chromium-based material such as chromium, chromium oxide, chromium nitride, chromium oxynitride or the like; Molybdenum-based materials such as molybdenum and molybdenum silicide; gold and the like can be used. When the functional film 6 (first to third functional films 61 to 63) has a light absorption (absorption) function, the material may be an inorganic material such as zirconium dioxide or cerium oxide, or a triazine compound. One of organic materials such as benzophenone series, benzotriazole series and benzoate series may be used, or a combination of two or more of these may be used, and zinc oxide may also be used. A fine particle-containing resin material or the like obtained by containing fine particles of titanium oxide or the like in a binder resin may be used. Furthermore, when the functional film 6 (first to third functional films 61 to 63) has a low reflection function, magnesium fluoride, silicon oxide, aluminum oxide, titanium oxide or the like should be used as the material. Can. Furthermore, in the case where the functional film 6 (first to third functional films 61 to 63) has a water / oil repellent function, fluorine or the like can be used as the material.

  In the present embodiment, an adhesion layer is provided at least between the base material 2 and the first functional film 61 for the purpose of improving the adhesion of the first functional film 61 to the base material 2. It is also good. Needless to say, an adhesion layer may be provided also between the second functional film 62 and the third functional film 63 and the base material 2.

  As described later, the first functional film 61 functions as an etching stopper in the manufacturing process of the imprint mold 1 according to the present embodiment (progressed in the in-plane direction toward the pattern area PA of the imprint mold substrate 10 The function of stopping the etching can also be performed. Therefore, it is preferable to use, as a material constituting at least the first functional film 61, a material having resistance to the etching solution in accordance with the material constituting the base 2 and the etching solution corresponding thereto. For example, when the material constituting the substrate 2 is quartz glass and hydrofluoric acid is used as the etching solution, chromium-based material, molybdenum-based material, gold or the like is used as the material constituting the first functional film 61. Is preferred.

  The shape, size, and the like of the concavo-convex pattern 4 formed on the upper surface of the convex structure 3 depend on the shape, size, and the like required for a product or the like manufactured using the imprint mold 1 according to the present embodiment. It may be set appropriately. For example, examples of the shape of the concavo-convex pattern 4 include a line and space shape, a pillar shape, a hole shape, and a lattice shape. Moreover, the dimension of the uneven | corrugated pattern 4 may be set, for example to about 10 nm-200 nm.

  In the second surface 2 </ b> B of the base material 2, a recess 5 having a predetermined size may be formed. The formation of the depressions 5 makes it possible, in particular, at the time of imprinting using the imprint mold 1 according to the present embodiment, particularly at the time of contact with the imprint resin 101 (see FIG. 13B) or the imprint mold 1 At the time of peeling, the upper surface of the substrate 2, in particular, the convex structure 3 can be curved. As a result, when the upper surface 31 of the convex structure 3 and the imprint resin 101 are brought into contact with each other, a gas is trapped between the concavo-convex pattern 4 formed on the upper surface 31 of the convex structure 3 and the imprint resin 101. In this case, the imprint mold 1 can be easily peeled off from the transfer pattern formed by transferring the concavo-convex pattern 4 to the imprint resin 101.

  The plan view shape of the recess 5 is preferably a substantially circular shape. The imprint mold has a substantially circular shape, and in particular, when the upper surface 31 of the convex structure 3 and the imprint resin 101 are brought into contact or when the imprint mold 1 is peeled off from the imprint resin 101. The upper surface 31 of the convex structure 3 of 1 can be curved substantially uniformly in the plane.

  As shown in FIG. 6, the size of the depression 5 in plan view is large enough to include the convex structure 3 in a projection area obtained by projecting the depression 5 to the first surface 2A of the substrate 2. There is no particular limitation as far as it is. If the projection area has such a size that the projection structure 3 can not be included, the entire upper surface of the projection structure 3 of the imprint mold 1 may not be effectively curved.

[Method of manufacturing imprint mold]
An example of the manufacturing method of the imprint mold 1 which has the structure mentioned above is demonstrated. FIG.7 and FIG.8 is a process flowchart which shows each process of the manufacturing method of the imprint mold which concerns on this embodiment by a cutting end surface.

[Substrate preparation process]
First, an imprint mold substrate 10 is prepared. As shown in FIG. 7A, the imprint mold substrate 10 has a base 2 having a first surface 2A and a second surface 2B opposite to the first surface 2A, and a plan view of the base 2 on the first surface 2A side. It has a protruding portion 30 located at a central portion and protruding from the first surface 2A, and a recessed portion 5 formed in a substantially central portion in plan view on the second surface 2B side of the base material 2. In the substrate 10 for an imprint mold, the same components as those of the imprint mold 1 according to the present embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted.

  The size of the protrusion 30 can be appropriately set according to the size of the convex structure 3 of the imprint mold 1 according to the present embodiment, and for example, the size of the substantially rectangular convex structure 3 ( For example, the length of one side may be about 200 μm or more larger than 33 mm ± 1 μm × 26 mm ± 1 μm.

  In the present embodiment, a first hard mask layer 70 is formed on the first surface 2A of the base material 2 of the imprint mold substrate 10 and the upper surface of the protrusion 30. Examples of the material constituting the first hard mask layer 70 include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium compounds such as chromium nitride, chromium oxide and chromium oxynitride, tantalum oxide, tantalum oxynitride, Tantalum oxide boride, tantalum compounds such as tantalum oxynitride boride, titanium nitride, silicon nitride, silicon oxynitride and the like can be used alone or in combination of two or more selected arbitrarily.

  The first hard mask layer 70 is patterned in a process to be described later (see FIG. 7D), and a substantially square annular groove 301 (see FIG. 7E) is formed on the protrusion 30 of the imprint mold substrate 10. It is used as a mask when forming by etching. Therefore, it is preferable to select the constituent material of the first hard mask layer 70 in consideration of the etching selectivity and the like according to the type of the imprint mold substrate 10. For example, when the imprint mold substrate 10 is a quartz glass substrate, a chromium oxide film or the like may be suitably selected as the first hard mask layer 70.

  The thickness of the first hard mask layer 70 is the etching selectivity according to the type of the substrate 10 for imprint mold, the length of the first functional film 61 in the imprint mold 1 to be manufactured (in the thickness direction of the substrate It is set appropriately in consideration of the length along the line) and the like. For example, when the imprint mold substrate 10 is a quartz glass substrate and the first hard mask layer 70 is a chromium oxide film, the thickness of the first hard mask layer 70 is appropriately in the range of about 1 nm to 20 nm. It can be set.

  The method for forming the first hard mask layer 70 on the first surface 2A of the base 2 of the imprint mold substrate 10 and the upper surface of the protrusion 30 is not particularly limited. For example, sputtering, PVD (Physical (Physical) Known film forming methods such as vapor deposition) and CVD (chemical vapor deposition) can be mentioned.

[First resist pattern forming process]
Next, a first photoresist layer 71 is formed by spin coating or the like so as to cover the first surface 2A of the imprint mold substrate 10 and the first hard mask layer 70 on the protrusion 30 (FIG. B) (refer to FIG. 7), an opening corresponding to a substantially square annular groove 301 (see FIG. 7E) formed in the protrusion 30 by subjecting the first photoresist layer 71 to exposure and development processing. To form a first resist pattern 72 (see FIG. 7C). The material constituting the first photoresist layer 71 is not particularly limited, and for example, a negative or positive photosensitive material can be used, but it is preferable to use a positive photosensitive material. .

  Although the film thickness of the first resist pattern 72, that is, the film thickness of the first photoresist layer 71 is not particularly limited, in the present embodiment, the substantially square annular groove 301 (FIG. After the formation of E), the first resist pattern 72 is left. Therefore, the film thickness of the first resist pattern 72 (the film thickness of the first photoresist layer 71) can be appropriately set according to the depth of the substantially rectangular annular groove 301 and the film reduction amount of the first resist pattern 72. .

  In the present embodiment, the convex structure of the imprint mold 1 is formed by the substantially rectangular annular groove 301 (see FIG. 7E) formed by the process described later, that is, the position where the opening of the first resist pattern 72 is formed. The size of the pattern area PA on the upper surface 31 of the portion 3 is determined. Therefore, the pattern area PA of the upper surface 31 of the convex structure 3 of the imprint mold 1 can be formed with high accuracy. Further, the film thickness of the first functional film 61 in the imprint mold 1 is determined by the dimension (width in the short direction) of the opening of the first resist pattern 72. Therefore, the dimension of the opening of the first resist pattern 72 is set to, for example, 50 nm or more, preferably 100 nm or more, in accordance with the film thickness of the first functional film 61, whereby the film thickness of the first functional film 61 Can be controlled with high precision.

[First Hard Mask Pattern Forming Step]
Using the first resist pattern 72 formed as described above as an etching mask, the first hard mask layer 70 exposed from the opening is dry etched using, for example, a chlorine-based (Cl ₂ + O ₂ ) etching gas. Thus, the first hard mask pattern 73 is formed on the protrusion 30 of the imprint mold substrate 10 (see FIG. 7D).

[Groove formation process]
The dry etching process is performed on the imprint mold substrate 10 using the first hard mask pattern 73 formed as described above as an etching mask to form a substantially square annular groove 301 on the protrusion 30 (FIG. 7). See (E)). When forming the groove 301, the correlation between the formation conditions (etching conditions etc.) of the groove 301 and the depth of the groove 301 is obtained in advance, and the groove 301 is made to have a desired range. The formation conditions (e.g., etching conditions) of the above may be set. The above-mentioned correlation forms a slot in sample substrate (substrate of the same material as substrate 10 for imprint mold) on predetermined conditions (etching conditions etc.), and shows a section (section along the thickness direction) of the sample substrate concerned. Is observed by a scanning electron microscope (SEM) or the like to obtain the depth of the groove.

[First functional film formation step]
The substantially rectangular annular groove 301 formed as described above is filled with a material (for example, a chromium-based material, a molybdenum-based material, gold or the like) that constitutes the first functional film 61, and the first functional film 61 is formed. (See FIG. 8A). It is preferable to fill the above material so that the upper end portion of the first functional film 61 is substantially flush with the first hard mask pattern 73 on the protrusion 30. When the above-described material is filled into the substantially rectangular annular groove portion 301, the above-described material is also laminated on the remaining first resist pattern 72. The above-described material stacked on the first resist pattern 72 may be removed at the same time as the first resist pattern 72 is removed in the process described later.

  The first functional film 61 functions as an etching stopper at the time of wet etching the protrusion 30 in a process described later. Therefore, as a material which comprises the 1st functional film 61, the material (for example, chromium system material, molybdenum system material, gold etc.) which has resistance to the etching liquid in the process mentioned below is used suitably.

  The substantially rectangular annular groove 301 formed in the groove forming step (see FIG. 7E) has a size corresponding to the size of the first hard mask pattern 73 (the size of the opening of the first resist pattern 72). It is formed by Then, the first hard mask pattern 73 (the opening of the first resist pattern 72) is formed with a dimension corresponding to the film thickness of the first functional film 61. Therefore, the first functional film 61 formed by being filled in the substantially rectangular annular groove 301 is formed to have a desired film thickness.

  Prior to filling the material constituting the first functional film 61 into the groove portion 301, an adhesion layer capable of improving the adhesion between the first functional film 61 and the imprint mold substrate 10 is formed on the surface of the groove portion 301. You may In the wet etching process described later, wet etching is performed on the imprint mold substrate 10 until the first functional film 61 is exposed. At this time, the gap between the first functional film 61 and the imprint mold substrate 10 If the etching solution intrudes into the surface, the surface (the interface with the first functional film 61) of the imprint mold substrate 10 may be roughened. If the surface of the imprint mold substrate 10 is roughened, the functional film 6 (particularly, the first functional film 61) may be peeled off from the imprint mold 1. However, the formation of the adhesion layer makes it difficult for the etching solution to penetrate into the gap between the first functional film 61 and the imprint mold substrate 10, and the surface of the imprint mold substrate 10 is not easily roughened. Thus, peeling of the functional film 6 from the imprint mold 1 can be suppressed.

[Second resist pattern forming step]
After the substantially rectangular ring shaped groove portion 301 is filled with the material forming the first functional film 61, the first resist pattern 72 and the material 61 ′ laminated on the first resist pattern 72 are formed (the first functional film 61 is formed The material is removed, and a second photoresist layer 74 is formed on the upper ends of the first hard mask pattern 73 and the first functional film 61 (see FIG. 8B). As a material forming the second photoresist layer 74, the same material as the material forming the first photoresist layer 71 may be used. Then, the second photoresist layer 74 is exposed and developed to form a second resist pattern 75 (see FIG. 8C).

  In the present embodiment, the second resist pattern 75 is formed so as to cover the first functional film 61 formed by being filled in the substantially rectangular annular groove 301 in plan view. That is, the second resist pattern 75 is formed such that the outer peripheral edge of the second resist pattern 75 surrounds the substantially rectangular first functional film 61 in plan view.

[Second Hard Mask Pattern Forming Step]
Using the second resist pattern 75 formed as described above as an etching mask, the exposed first hard mask pattern 73 is dry etched using, for example, a chlorine-based (Cl ₂ + O ₂ ) etching gas. The second hard mask pattern 76 is formed on the protrusion 30 of the imprint mold substrate 10 (see FIG. 8D).

[Wet etching process]
A wet etching process is performed on the imprint mold substrate 10 using the second hard mask pattern 76 formed as described above as an etching mask (see FIG. 8E). For example, hydrofluoric acid or the like is suitably used as the etching solution in the wet etching process.

  At the beginning of the wet etching process, the etching proceeds from the outer edge of the second hard mask pattern 76 downward (in the thickness direction of the substrate 10 for imprint mold) (see FIG. 10), gradually becoming the first functional film 61. The etching proceeds (in the in-plane direction of the imprint mold substrate 10) (see FIG. 11). That is, the etching proceeds isotropically. When the etching proceeds until the first functional film 61 is exposed, the etching in the in-plane direction of the imprint mold substrate 10 stops, and only the etching in the thickness direction of the imprint mold substrate 10 progresses (FIG. 12). reference). Then, the wet etching process is finished in a state in which the lower end portion of the first functional film 61 is embedded in the imprint mold substrate 10. Thereby, the first side surface portion 32 continuous to the upper surface 31 and the outer peripheral edge portion of the upper surface 31 and substantially perpendicular to the upper surface 31, the curved surface 33 continuous to the lower end portion of the first side surface portion 32, and the curved surface The convex structure 3 having a flat surface 34 continuous to the upper surface 31 and a second side surface 35 continuous to the outer peripheral edge of the flat surface 34 is a first structure of the imprint mold substrate 10. It is formed to protrude from the surface 2A. As a result, it has a base 2 having a first surface 2A and a second surface 2B opposite thereto, and the convex structure 3 integrally projecting from the side of the first surface 2A of the base 2, A first functional film 61 is formed in the portion 32, and a functional substrate 1 ′ is produced in which a part including the lower end portion of the first functional film 61 is located in the convex structure 3 (base material 2) be able to. The second functional film 62 and the third functional film 63 may be formed on the curved surface 33 and the flat surface 34 of the convex structure 3 of the functional substrate 1 ′.

[Concave and convex pattern formation process]
After the convex structure 3 is formed as described above, the third hard mask pattern 77 corresponding to the concavo-convex pattern 4 is formed on the upper surface 31 (pattern area PA) of the convex structure 3 of the functional substrate 1 ′. (See FIG. 9A). Then, the imprint mold 1 is manufactured by performing dry etching processing on the imprint mold substrate 10 using the third hard mask pattern 77 as a mask, and forming the concavo-convex pattern 4 on the upper surface of the convex structure 3 (see FIG. 9 (B)). The dry etching of the functional substrate 1 ′ can be performed by selecting an appropriate etching gas according to the type of the constituent material of the functional substrate 1 ′. As an etching gas, for example, a fluorine-based gas can be used.

[Imprinting method]
An imprint method using the imprint mold 1 having the above-described configuration will be described. FIG. 13 is a process flowchart showing each process of the imprint method in the present embodiment at a cut end surface.

  First, the imprint mold 1 and the transferred substrate 100 having the first surface 100A and the second surface 100B opposed to the first surface 100A are prepared (see FIG. 13A). The substrate to be transferred 100 is, for example, a quartz glass substrate, a soda glass substrate, a calcium fluoride substrate, a magnesium fluoride substrate, an acrylic glass or the like, or a laminate of two or more substrates arbitrarily selected therefrom. Transparent substrates such as laminated substrates; Metal substrates such as nickel substrates, titanium substrates, and aluminum substrates; and semiconductor substrates such as silicon substrates and gallium nitride substrates.

  Next, the imprint resin 101 is supplied to the first surface 100A of the transfer substrate 100 (see FIG. 13B). As the imprint resin 101, a conventionally known ultraviolet curable resin or the like can be used. The supply amount of the imprint resin 101 depends on the remaining film thickness of the pattern structure 102 (see FIG. 13D) manufactured by the imprint method in this embodiment, the volume of the concavo-convex pattern 4 of the imprint mold 1, and the like. Can be calculated and determined appropriately. At this time, in order to prevent generation of defects (unfilled defects) in the pattern structure 102 due to an insufficient supply amount of the imprint resin 101, the supply amount of the imprint resin 101 is determined by the remaining film thickness of the pattern structure 102 and The amount may be determined to be slightly larger than the amount calculated according to the volume of the concavo-convex pattern 4 of the imprint mold 1 or the like.

  Subsequently, the concavo-convex pattern 4 (pattern area PA) of the imprint mold 1 is brought into contact with the imprint resin 101, and the first surface 100A of the transfer substrate 100 and the concavo-convex pattern 4 (pattern area PA) of the imprint mold 1 The imprint resin 101 is developed between them. Then, in this state, the imprint resin 101 is irradiated with energy rays (UV etc.) through the imprint mold 1 to cure the imprint resin 101 (see FIG. 13C).

  In the present embodiment, the supply amount of the imprint resin 101 is slightly larger than the amount calculated according to the residual film thickness of the pattern structure 102, the volume of the concavo-convex pattern 4 of the imprint mold 1, and the like. Therefore, when the imprint resin 101 is developed between the first surface 100 A of the transfer substrate 100 and the concavo-convex pattern 4 (pattern area PA) of the imprint mold 1, the convex structure 3 of the imprint mold 1 The imprint resin 101 protrudes outside the upper surface 31 (pattern area PA). When energy beam (UV etc.) is irradiated through the imprint mold 1 to cure the imprint resin 101, the upper surface 31 (pattern area PA) of the convex structure 3 on the second surface 2B side of the imprint mold 1 is irradiated. Energy rays (UV and the like) also advance from the opposing region to a direction inclined to the thickness direction of the imprint mold 1 (a direction toward the protruding imprint resin 101) (see FIG. 5). However, since this energy ray (UV etc.) is shielded by the first functional film 61 of the imprint mold 1, it is possible to prevent the imprint resin 101 which has run out from curing.

  Finally, the imprint mold 1 is peeled off from the cured imprint resin 101 (see FIG. 13D). Thus, it is possible to manufacture the pattern structure 102 in which the concavo-convex pattern 4 of the imprint mold 1 is transferred onto the first surface 100A of the transfer substrate 100.

  The embodiments described above are described to facilitate the understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents that fall within the technical scope of the present invention.

  In the above embodiment, the functional film 6 is provided on the first functional film 61 provided on the first side surface 32 of the convex structure 3, the second functional film 62 provided on the curved surface 33, and the flat surface. Although the embodiment including the third functional film 63 provided in 34 has been described as an example, the present invention is not limited to this embodiment. For example, the functional film 6 provided on the imprint mold 1 or the functional substrate 1 ′ may include at least the first functional film 61 provided on the first side surface portion 32, and the second functional film 62 and the third functional film 63 may not be included, and the second functional film 62 may be included but the third functional film 63 may not be included.

  In the above embodiment, although the first to third functional films 61 to 63 all have the same function, they are described as an example, but the present invention is not limited to this aspect. For example, one of the first to third functional films 61 to 63 may exhibit different functions, or all may exhibit different functions. In this case, the first functional film 61 may have a function as an etching stopper in the process of manufacturing the imprint mold 1. Moreover, one of the first to third functional films 61 to 63 may be made of different materials, or all of them may be made of different materials.

  In the above embodiment, although an example in which each of the first to third functional films 61 to 63 is constituted by one layer has been described as an example, the present invention is not limited to this aspect, and a plurality of layers You may be comprised by the laminated body. For example, the first to third functional films 61 to 63 may be formed by laminating a functional film having a water / oil repellent function on a functional film having a light shielding function, or light absorption A functional film having a low reflection function may be stacked on a functional film having an (absorption) function, and a functional film having a water / oil repellent function may be further stacked if desired.

  In the said embodiment, although the aspect which the convex structure part 3 protrudes integrally from 1st surface 2A of the base material 2 was mentioned as the example, and demonstrated, it is not limited to this aspect. For example, the convex structure 3 separately from the substrate 2 may be bonded directly to the first surface 2A of the substrate 2 or via an adhesive or the like. Further, as shown in FIGS. 14A and 14B, the hollow cylindrical support portion 21, the thin plate portion 22 having the first surface 22A and the second surface 22B opposed thereto, and the first thin plate portion 22. It has the convex structure 3 protruding from the surface 22A and the concavo-convex pattern 4 formed on the upper surface 31 of the convex structure 3 so that the opening end 51 of the support 22 is closed by the second surface 22B The thin plate portion 22 may be joined to the plate 21. The recessed portion 5 is formed by the thin plate portion 22 being joined to the support portion 21. In the embodiment shown in FIGS. 14A and 14B, a functional film 6 (first film) that covers the first side surface portion 32, the curved surface 33 and the flat surface 34 of the convex structure 3 of the thin plate portion 22 (first The imprint mold 1 can be manufactured by forming the third functional film 61 to 63) and bonding the thin plate portion 22 to the support portion 21.

  In the embodiment described above, the aspect in which the substantially square annular groove portion 301 is formed by the dry etching process using the first hard mask pattern 73 as a mask has been described as an example, but it is not limited to this aspect. For example, the groove portion 301 having a substantially rectangular ring shape may be formed by cutting the projecting portion 30.

  In the above embodiment, the film thickness of the first resist pattern 72 is set such that the first resist pattern 72 remains even after the substantially rectangular annular groove 301 is formed by dry etching. Although explained, it is not limited to this aspect. For example, the first resist pattern 72 may be formed to a thickness that does not leave the first resist pattern 72 after the substantially rectangular annular groove 301 is formed by the dry etching process, or the first hard mask pattern 73 may be formed. After forming the first resist pattern 72, the substantially rectangular annular groove 301 may be formed by dry etching using the first hard mask pattern 73 as a mask. In this case, prior to filling the material forming the first functional film 61 into the substantially rectangular annular groove 301, a resist pattern or the like having an opening corresponding to the substantially rectangular annular groove 301 may be formed.

  In the above embodiment, the imprint mold substrate 10 having the projecting portion 30 protruding from the first surface 2A is prepared (see FIG. 7A), and the functional substrate 1 ′ is manufactured using the imprint mold substrate 10. (See FIGS. 7B to 8E), and finally, an embodiment of manufacturing the imprint mold 1 by forming the concavo-convex pattern 4 on the upper surface 31 of the convex structure 3 is described as an example. However, it is not limited to this aspect (see FIG. 9). For example, a substrate for imprint mold in which a concavo-convex pattern 4 is formed on the upper surface of the protrusion 30, and a protective film (such as a resist film) 70 'for protecting the concavo-convex pattern 4 and the first hard mask layer 70 are formed in order. Prepare 10 ′ (see FIG. 15), and carry out the steps (see FIGS. 7B to 8E) of producing the functional substrate 1 ′ using the substrate for imprint mold 10 ′. Thus, the imprint mold 1 may be manufactured. In the imprint mold substrate 10 'shown in FIG. 15, a protective film (such as a resist film) 70' is formed between the first hard mask layer 70 and the first surface 2A of the base 2 outside the protrusion 30. It may be formed.

DESCRIPTION OF SYMBOLS 1 imprint mold 1 'functional substrate 2 base material 2A 1st surface 2B 2nd surface 3 convex structure part 31 upper surface 32 1st side part 33 curved surface 34 flat surface 35 the 1st 2 Side surface portion 6 ... functional film 61 ... first functional film 62 ... second functional film 63 ... third functional film

Claims (16)

A substrate having a first surface and a second surface opposite to the first surface;
And a convex structure portion protruding from the first surface side of the base material,
The convex structure portion is continuous with an upper surface, an outer edge of the upper surface, and a first side surface extending downward along the thickness direction of the base, a flat surface continuous with a lower end of the first side surface, and the flat surface. A second side surface continuous with the outer edge of the surface and extending in a direction toward the first surface;
A first functional film is formed on the first side surface,
The functional substrate in which a portion including the lower end portion of the first functional film is located in the convex structure. The functional substrate according to claim 1, wherein the first functional film is made of a material having resistance to an etching solution that can be applied to the substrate. The substrate is made of a material transparent to energy rays of a predetermined wavelength,
The functional substrate according to claim 1, wherein the first functional film is made of a material having a light shielding performance to the energy ray. The functional substrate according to any one of claims 1 to 3, wherein the first functional film is made of a chromium-based material, a molybdenum-based material or gold. The first side surface and the flat surface are continuous via a curved surface located therebetween,
The function according to any one of claims 1 to 4, wherein a second functional film continuous to a predetermined position of the first functional film formed on the first side surface is formed on the curved surface. Substrate. The functional substrate according to claim 5, wherein a third functional film that is continuous with the second functional film is formed on the flat surface. The functional substrate according to any one of claims 1 to 6, wherein a length of the first side surface in a thickness direction of the base material is 0.2 μm to 2 μm. Preparing a base material having a first surface, a second surface opposite to the first surface, and a protrusion projecting from the first surface;
Forming in the upper surface of the protrusion a groove surrounding the outer periphery of a predetermined region included in the upper surface of the protrusion;
Filling the groove with a functional material;
Forming a hard mask pattern having dimensions larger than the predetermined area on the upper surface of the protrusion so as to physically include the predetermined area;
Using the hard mask pattern as an etching mask and wet etching the upper surface of the protrusion to a predetermined depth using a predetermined etching solution,
A method of manufacturing a functional substrate, comprising wet etching the upper surface of the protrusion so as to expose a part of the functional material filled in the groove but not expose the whole. 9. The method of manufacturing a functional substrate according to claim 8, wherein the upper surface of the protrusion is wet-etched so as to position the lower end portion of the functional material filled in the groove portion in the substrate. The method for producing a functional substrate according to claim 8, wherein the functional material is a material having resistance to the etching solution. The substrate is made of a material transparent to energy rays of a predetermined wavelength,
The method for producing a functional substrate according to any one of claims 8 to 10, wherein the functional material is a material having a light shielding performance to the energy ray. The function according to any one of claims 8 to 11, further comprising the step of forming a functional material film on the surface of the base surrounding the outer side of the groove, which appeared by wet etching the upper surface of the protrusion. Method of a flexible substrate. The said groove part is formed by etching the upper surface of the said protrusion part via the mask pattern which has the opening part corresponding to the said groove part formed in the upper surface of the said protrusion part. Method of manufacturing functional substrate The method for manufacturing a functional substrate according to any one of claims 8 to 12, wherein the groove is formed by cutting the upper surface of the protrusion. The method for producing a functional substrate according to any one of claims 8 to 14, wherein an opening size of the groove portion is 50 nm or more. The functional substrate according to any one of claims 1 to 7;
An imprint mold comprising: a concavo-convex pattern formed in a pattern area set on an upper surface of the convex structure portion.

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