JP5884555B2 - Imprint mold and method for forming fine structure - Google Patents

Description

  The present invention relates to an imprint mold for forming a desired concavo-convex structure and a fine structure forming method using the same.

As a microfabrication technology, attention has been focused on an imprint method that uses a mold member (mold) with a fine concavo-convex structure formed on the surface of a substrate and transfers the concavo-convex structure to a transfer material to transfer the fine structure at the same magnification. Yes. In this imprint method, there is a peeling process in which a transfer material having fluidity is used, the mold is pressed, the uneven structure of the mold is filled with the transfer material, cured, and then the mold and the transfer material are separated. . In this peeling process, there is a demand for a technique for cleanly peeling the mold and the transfer material while maintaining the concavo-convex structure transferred to the transfer material on the substrate. In general, the risk of inconvenience that the transfer material adheres to the mold during peeling and the risk of breakage of the mold have a correlation with the peeling force required for peeling. In particular, when the increase or decrease in peeling force (N or Pa) per unit time (msec) is expressed in terms of load speed (N / msec or Pa / msec), the absolute value of this load speed increases. This indicates that there was a steep increase / decrease in the peeling stress with respect to the point or the surface where the phenomenon occurred. When the strength of the transfer material or the adhesion between the transfer material and the substrate cannot withstand the peeling force, the transfer material adheres to the mold or the transfer material is damaged.
In order to suppress the occurrence of the load speed described above, it is preferable to reduce the peeling force. For example, a method of forming a release layer containing a fluorine component or the like on the uneven structure surface of the mold (Patent Document 1). Proposed. In addition, a method (Patent Document 2) that suppresses a rapid increase in peeling force by providing a dummy pattern has also been proposed. Furthermore, an apparatus (Patent Document 3) that measures the peeling force and controls it to achieve a target peeling force has been proposed.

Japanese Patent No. 4154595 JP 2010-225683 A JP 2010-274635 A

However, in the method of providing a release layer on the concavo-convex structure surface of the mold described above, when multiple types of concavo-convex structures exist in the mold, the stress required for peeling varies for each concavo-convex structure region. There is a problem that the possibility of an increase in the load speed cannot be excluded. Even if the uneven structure of the mold is uniform, when the contact area increases for the purpose of improving productivity, the force required for peeling increases dramatically, and the problem with peeling is solved. Is not enough. Furthermore, when the releasing action of the releasing layer is too large, there is a problem that the filling property of the transfer material into the uneven structure of the mold is lowered.
Further, in the method of forming a dummy pattern, even a pattern that is not originally required is transferred, and thus the peeling pattern may have an adverse effect in the subsequent process.
Furthermore, since the change in load speed can occur even in a very short time in units of msec, the apparatus that measures the peeling force as described above and controls it to achieve the target peeling force detects the change in the load speed. However, it is difficult to feed back this and respond instantaneously, and if instantaneous response is possible, it is considered that the cost of the apparatus is greatly increased.
The present invention has been made in view of the above circumstances, and provides an imprint mold capable of stably peeling from a transfer material, and a method for forming a microstructure using the mold. Objective.

In order to achieve such an object, the present invention provides a mold having a concavo-convex structure on a main surface of a substrate, and the transfer material is peeled from the mold after the concavo-convex structure is filled with a transfer material and cured. In the imprint mold for transferring the concavo-convex structure to the transfer material, the peeling direction between the transfer base material and the mold is a specific direction, and the main surface of the base material has a plurality of concavo-convex structures. area is positioned to be adjacent along said specific direction, as the stress required for peeling of the transfer material of each region, the increasing tendency toward a specific region from a region located at both ends of the specific direction, a plurality It was set as the structure where the said area | region of was located.
As another aspect of the present invention, the ratio S / A of the measured surface area S of the region to the area A of each of the plurality of regions tends to increase from the region located at both ends in the specific direction toward the specific region. A certain configuration was adopted.
As another aspect of the present invention, the ratio L / B of the measured length L to the region length B in the specific direction in each region tends to be the same or increasing from the region located at both ends of the specific direction toward the specific region. The configuration is as follows.

As another aspect of the present invention, the main surface is a square, and the specific direction is a direction from one end side to the other end side of the main surface, or from one corner portion of the main surface facing each other. It was set as the structure which is the direction which goes to the other corner | angular part.
As another aspect of the present invention, the main surface is a regular N-gon (N is an integer of 5 or more), and the specific direction is a direction from one opposite side of the main surface to the other end, or It was set as the direction which goes to the other edge part from the one corner | angular part which the main surface opposes, or the direction which goes to the other corner | angular part from the one corner | angular part which the main surface opposes.
As another aspect of the present invention, the main surface is circular and the specific direction is arbitrarily set.
As another aspect of the present invention, the main surface is elliptical, and the specific direction is the major axis direction of the elliptical shape of the main surface.
As another aspect of the present invention, the main surface is an annular shape having an opening, and the specific direction is a direction from an outer edge of the main surface toward an inner edge on the opening.

The fine structure forming method of the present invention includes a pressing step in which a transfer material is interposed between the main surface of one of the above-described imprint molds and a substrate, a curing step in which the transfer material is cured, and curing. A peeling step of peeling off the transfer material and the mold later, and in the peeling step, the peeling force is increased so as to widen the gap distance between the base and the mold along the specific direction of the mold. It was set as the structure which acts.
Further, the present invention is a mold having a concavo-convex structure on the peripheral surface of a cylindrical substrate, and after the transfer material is filled and cured in the concavo-convex structure, the transfer material is peeled off from the mold, and the concavo-convex structure In the imprint mold for transferring the material to the transfer material, the circumferential surface of the cylindrical base material is uneven along the circumferential direction from one base line portion perpendicular to the circumferential direction of the circumferential surface. A plurality of regions having a structure are positioned adjacent to each other, and the stress required for peeling the transfer material for each region tends to increase from the adjacent region to the specific region along the circumferential direction so as to sandwich the base line portion. It was set as the structure where the said several area | region is located so that it may become.
As another aspect of the present invention, the ratio S / A of the measured surface area S of the region to the area A in each region of the plurality of regions is along the circumferential direction from adjacent regions so as to sandwich the baseline region, respectively. The configuration tends to increase toward a specific area.
As another aspect of the present invention, the ratio L / B of the measured length L to the circumferential region length B in each region is changed from the adjacent region to the specific region along the circumferential direction so as to sandwich the baseline portion. The configuration is the same or tends to increase.

  The fine structure forming method of the present invention includes a pressing step of pressing a transfer material disposed on a substrate and any of the above-described cylindrical imprint molds, and the mold in the circumferential direction. While making n rotations (n is an integer of 1 or more), the transfer base material is cured in contact with the mold, the cured transfer material and the mold are peeled off, and the transfer material is transferred to the mold. A transfer / curing / peeling process for transferring the concavo-convex structure, and in the pressing process, the base part of the mold is pressed against a transfer material, and in the transfer / curing / peeling process, the base part of the mold is The configuration is such that the rotation is stopped in contact with the transfer material.

  In the present invention, when the mold and the transfer material are peeled in a specific direction or a circumferential direction, a steep increase / decrease in peeling stress can be suppressed, stable imprinting is possible, and the occurrence of defects is reduced. It is possible to form a fine structure.

FIG. 1 is a side view of a mold for explaining an embodiment of a mold for imprinting according to the present invention. FIG. 2 is a plan view of the main surface of the substrate of the imprint mold shown in FIG. FIG. 3 is a diagram for explaining the ratio L / B in the present invention. FIG. 4 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. FIG. 5 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. FIG. 6 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. FIG. 7 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. FIG. 8 is a plan view corresponding to FIG. 2, showing another embodiment of the imprint mold of the present invention. FIG. 9 is a perspective view showing another embodiment of the imprint mold of the present invention. 10 is a cross-sectional view perpendicular to the rotation axis of the mold shown in FIG. FIG. 11 is a process diagram for explaining an embodiment of the fine structure forming method of the present invention. FIG. 12 is a process diagram for explaining another embodiment of the fine structure forming method of the present invention. FIG. 13 is a process diagram for explaining another embodiment of the fine structure forming method of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Imprint mold]
The mold for imprinting of the present invention is a mold having a plurality of types of concavo-convex structures, and the peeling direction between the transfer material and the mold at the time of imprinting is set in advance as a specific direction, and the peeling stress in this specific direction is steep. A plurality of regions having a concavo-convex structure are arranged so as to suppress the change. In addition, the shape and size of the concavo-convex structure possessed by a plurality of regions, and the type of the concavo-convex structure can be set and selected as appropriate. Then, each region may be positioned so that the stress required for peeling the transfer material for each region tends to increase from the region located at both ends in the specific direction toward the specific region. In particular, as a condition in which the difference in the adhesion force appears and the arrangement method thereof, the ratio S / A of the measured surface area S of the region to the area A in each region is changed from the region located at both ends in the specific direction to the specific region. There is a condition that satisfies a tendency toward an increase toward the center, or an increase trend toward a specific area along the circumferential direction from each of the adjacent areas so as to sandwich the baseline portion. Therefore, if these conditions are obeyed, there is no particular limitation.

<Embodiment 1>
FIG. 1 is a side view of a mold for explaining an embodiment of an imprint mold according to the present invention, and FIG. 2 is a plan view of a substrate main surface of the imprint mold shown in FIG. It is. 1 and 2, the imprint mold 11 has a base 12, and a rectangular main surface 13 of the base 12 has a concavo-convex structure region 13 </ b> A having a concavo-convex structure to be transferred. A non-concave structure region 13B that does not have an uneven structure is set. In FIG. 1, uniform fine unevenness is shown in the uneven structure region 13A of the main surface 13, but this shows the uneven structure for convenience. Further, the non-concave structure region 13B may not exist, and the entire main surface 13 may be the uneven structure region 13A.
In the concavo-convex structure region 13A of the main surface 13, the concavo-convex structure is formed along a specific direction (the direction of arrow D shown in FIG. 2) from one end side 13a to the other end side 13b of the rectangular main surface 13. A plurality of regions III, II, I, II ′, and III ′ having a position are adjacent to each other. In the present invention, when the stress required for peeling of the transfer material in each of the regions III, II, I, II ′, and III ′, that is, the adhesion force is obtained, the adhesion force is located at both ends in the specific direction D. There is a tendency to increase from regions III and III ′ toward region I as a specific region. Note that the shape and size of the concavo-convex structure possessed by the plurality of regions and the type of the concavo-convex structure can be set and selected as appropriate, and there is no particular limitation.

  In this example, the increasing tendency means that the adhesion force gradually increases from the region III to the region II and further toward the specific region I, and from the region III ′ to the specific region II ′ and further to the specific region. That is, the adhesion force gradually increases toward the region I. For example, the case where the adhesion force in the region III and the region II is the same, or the adhesion force in the region III ′ and the region II ′ is the same is included. Further, the adhesion force in the region II and the region II ′ located on both sides of the region I may be the same or different, and the adhesion force in the region III and the region III ′ located outside thereof is also the same. , Different ones may be used. The same applies to the following present invention.

  Here, a method for obtaining the stress required for peeling of the transfer material for each region, that is, the adhesion force will be described. The simplest method is, for example, preparing a sample mold A and a sample mold B having the same pattern shape as the concavo-convex structure pattern of the region I and the region II and having the same area, and using them in the transfer respectively Applying and curing the transfer material and measuring the stress required to peel off the transfer material. The method of peeling is preferably matched to the method of peeling when nanoimprinting is performed, and a method of applying a stress in the vertical direction between the transfer material and the sample mold, or from the lateral direction with respect to the sample mold and / or transfer material If it is possible to bend the sample mold and / or the transfer material, it is possible to perform peeling by applying stress to the end of the sample mold. Moreover, the site | part where the stress required for peeling off a transfer material is measured by these peeling methods. For example, when peeling off in the vertical direction, since the force can be regarded as being applied uniformly to the surface, the stress is measured over the entire area of the region. In addition, even when the contact surface is gradually peeled even in the above vertical peeling method, for example, when the sample is bent and peeled, the boundary between the peeled portion and the non-peeled portion becomes a line, Stress is measured at this boundary line.

  By the way, the above is a comparison of stresses required to peel each sample mold from the transfer material. That is, it is a relative evaluation between sample molds when the transfer material is used as a reference. However, if it is desired to simply rank the sample molds, for example, the sample mold A and the sample mold B are joined via the transfer material, and the sample mold A and the sample mold B are subjected to equal stress. In other words, the order of peeling from the transfer material is measured first, that is, relative evaluation of the adhesion force in each sample mold is performed, and this may be used as the adhesion force. Furthermore, these data may be collected in advance, and the relative difference in adhesion may be obtained by comparing with the data.

As described above, the method of arranging the regions in a permutation manner according to the magnitude of the adhesion force has been presented, but even when such an adhesion force measurement is not performed, the fact that the adhesion force value varies depending on the surface area is utilized. In particular, it is possible to use the area A in each region and the actually measured surface area S as judgment criteria. Next, a case where this determination criterion is adopted will be described.
In the above example, the concave-convex structure region 13A of the main surface 13 has a specific direction (in the direction of arrow D shown in FIG. 2) from the opposite end 13a to the other end 13b of the rectangular main surface 13. A plurality of regions III, II, I, II ′, and III ′ having a concavo-convex structure are adjacent to each other. In the present invention, when the ratio S / A of the measured surface area S of the region III to the region A of each region III, II, I, II ′, III ′ is obtained, the ratio S / A is determined to be in the specific direction D. Tends to increase from the regions III and III ′ located at both ends of the region toward the region I as the specific region. Note that the shape and size of the concavo-convex structure possessed by the plurality of regions and the type of the concavo-convex structure can be set and selected as appropriate, and there is no particular limitation. At this time, as a method of obtaining the measured surface area S, a method of obtaining from a numerical value obtained by observing the shape using SEM, AFM, or the like, scatterometry or the like can be used.

Here, the usefulness of each measurement method for obtaining the measured surface area S and an effective usage method will be described. The SEM is a representative example of shape observation from the upper part of the surface, and the optical microscope belongs to this. Therefore, although unevenness information is difficult to obtain, it can be said to be a very effective means for measuring dimensions. If the focus margin permits, it is possible to obtain information on the distance between the focal points, that is, the depth, because the bottom of the concavo-convex structure pattern can be observed from the pattern opening. Therefore, in the case where importance is given to planar information such as the edge shape constituting the dimensions and shape of the concavo-convex structure pattern, and the depth is only required to be an approximate value, it is an effective measurement method.
The AFM is a representative example of an observation method that obtains shape information by substantially tracing the surface of a measurement object with a probe (cantilever), and a contact type step meter belongs to this. The feature of this measurement method is that accurate depth information can be obtained if the probe (cantilever) can trace the surface accurately. Therefore, this method is effective when the depth information of the concavo-convex structure pattern is to be emphasized. Of course, this measurement method may be combined with other methods such as SEM, which is the same for SEM.

  In contrast to these measurement methods, scatterometry is a method for obtaining a shape on the assumption that the optical properties within the region to be measured are uniform, so complex pattern shapes and random pattern arrangements are used. However, it is difficult to use it for complicated objects with different optical properties, such as when it has a layer structure with different refractive index, and it is low in versatility unlike SEM and AFM unless a measurement technique exceeding this assumption is established. . However, if the assumption is satisfied, it is possible to know the side wall shape in addition to the dimension and depth of the pattern with a single measurement, so that the measured surface area S can be measured more strictly. Therefore, in the present invention, it can be said to be a preferable method for measuring a surface having a concavo-convex structure pattern of several microns or less, particularly submicron or less. Further, scatterometry is also preferable in that the damage to the mold is low. For example, if a high-energy and low-wavelength electromagnetic wave such as SEM is irradiated, if a thin film having releasability is formed on the mold surface, this thin film is damaged, resulting in a transfer failure during imprinting. Even with a method in which the measurement part approaches or comes into contact like AFM, there is a risk of foreign matter being attached or damaged, or a change in surface condition. Therefore, it can be said that the scatterometry which performs non-contact measurement using a laser beam is a particularly preferable method assuming the case where a mold is used after measurement. From the standpoint of non-contact and damage-free, a measurement method having a measurement system using low energy light, in particular, light having a wavelength of 222 nm or more with low damage to the release layer is preferable. You may use a measuring apparatus (for example, Mitaka Kogyo Co., Ltd. product NH-3SP etc.) and a laser microscope according to the uneven | corrugated structure pattern to measure. In addition, these methods may be used in combination with other measurement methods similarly to SEM and AFM.

The measured surface area S may be obtained without performing the above measurement. For example, the surface area may be calculated from the design data of the concavo-convex structure pattern, and this may be used as an alternative value. For example, the shape information of the concavo-convex structure pattern may be measured by SEM, and the depth information may be combined with measurement and calculation, such as using design data.
In this example, the ratio S / A gradually increases from the region III to the region II and further to the region I which is the specific region, and from the region III ′ to the region II ′ and further to the region I which is the specific region. The ratio S / A gradually increases. For example, this also includes the case where the ratio S / A in the region III and the region II is the same, or the ratio S / A in the region III ′ and the region II ′ is the same. Further, the ratio S / A between the region II and the region II ′ located on both sides of the region I may be the same or different, and the ratio S between the region III and the region III ′ located outside the region I is different. / A may be the same or different. The same applies to the following present invention.

The area A is an area determined for each region. For example, in a rectangular region of 2 mm × 6 mm, the area A is 12 mm ² . The areas A in the regions III, II, I, II ′, and III ′ may be the same or different. On the other hand, the measured surface area S of each of the set regions III, II, I, II ′, and III ′ is measured using SEM, AFM, scatterometry, etc. It can be calculated from the data. Thereby, the ratio S / A is calculated. The larger the ratio S / A, the larger the contact area between the mold and the transfer material per unit area in the region, and the greater the stress required for peeling between the mold and the transfer material. In the present invention, the concavo-convex structure of the regions III, II, I, II ′, III ′ is a specific region from the regions III, III ′ in which the ratio S / A is located at both ends in the specific direction D as described above. If there is an increasing tendency toward the area I, there is no particular limitation. Therefore, all the uneven structures of the five regions III, II, I, II ′, III ′ in this example may be different, and, for example, the uneven structure of the region III and the region III ′ is the same. The uneven structure of II and region II ′ may be the same.

  In addition, when the concavo-convex structure of the mold is directional, such as a line and space pattern or a pattern having a direction in the arrangement interval of the concave or convex portions, generally, the stress required for peeling in consideration of the pattern shape of the mold Peeling is performed from the direction of small. However, if the uneven structure of the regions III, II, I, II ′, and III ′ includes the presence or absence of peeling directionality or a difference in the degree of peeling direction, the peeling stress is steep at the boundary of the set region. Changes may occur, and the relationship between the specific direction D and the peeling direction becomes important. Therefore, in the present invention, in addition to the above requirement of the ratio S / A, attention is paid to the ratio L / B of the actually measured length L to the region length B in the specific direction D, and the regions III, II, I, II ′, III ′. It is preferable that the ratio L / B in each of the above regions tends to be the same or increase from the regions III and III ′ located at both ends of the specific direction D toward the region I that is the specific region.

The region length B is a length determined for each region. For example, in a region having a rectangular shape of 2 mm × 6 mm, the region length B is 2 mm in a region where the specific direction D coincides with the short side direction. . The region lengths B in the regions III, II, I, II ′, and III ′ may be the same or different. Further, the ratio L / B is calculated by obtaining the measured length L of each of the set regions III, II, I, II ′, and III ′. For example, in the example shown in FIG. 3A, the region length B, which is a plan view length in the specific direction D, and the actually measured length L in the specific direction D are equivalent. On the other hand, in the example shown in FIG. 3B, the actually measured length L in the specific direction D is larger than the region length B that is a plan view length in the specific direction D. 3C, the concavo-convex structure has protrusions or recesses that are isolated from each other, and the actual measurement length L in the specific direction D varies depending on the measurement site. ₁ , L ₂ , L _3, etc.) is measured, the average value is the measured length L. In addition, for example, in the case where a drum-shaped region with a narrowed central portion in the width direction and a drum-shaped region with a swollen central portion are alternately arranged along the specific direction D, the region length B in one region Will vary depending on the site. In this case, if the ratio L / B calculated in different parts of one region is constant, this is adopted. Further, when the calculated ratio L / B varies, the average value is set to the ratio L / B.

Here, the actual measurement length L is obtained by measurement at a plurality of measurement sites over the entire width direction (direction orthogonal to the specific direction D) of the region to be measured by using the above-described method for obtaining the actual measurement surface area S. . However, the difference from the case of obtaining the actually measured surface area S is that it is not always necessary to confirm the minimum dimension or the side wall shape of the concavo-convex structure, and it is only necessary to measure the actually measured length L in the specific direction D. For example, in FIG. 3A, even when the measured length L is sufficiently long even if the dimension in the direction perpendicular to the specific direction D is nanoscale, or when the entire region is diffracted by illumination light, Since it can be recognized by an optical observation system, for example, dimension measurement can be performed by an optical microscope without using an SEM. Further, it is preferable that the damage to the mold is small even when the measured length L is obtained. Therefore, it is preferable to use a measurement method having a measurement system using low energy light, in particular, light having a wavelength of 222 nm or more with low damage to the release layer.
As the ratio L / B is larger, the uneven structure of the mold in the specific direction D becomes more complicated and finer in the region, and the stress required for peeling between the mold and the transfer material increases.

In the present invention, various regions can be set within a range that satisfies the above-described requirement of the ratio S / A, and preferably within a range that satisfies the requirements of the ratio S / A and the ratio L / B. ) To (4) can be set.
(1)
Ratio S / A: Increase in order of III → II → I, increase in order of III ′ → II ′ → I Ratio L / B: Increase in order of III → II → I, increase in order of III ′ → II ′ → I (2)
Ratio S / A: Increase in order of III → II → I, increase in order of III ′ → II ′ → I Ratio L / B: Same (III = II = I = II ′ = III ′)
(3)
Ratio S / A: Increasing in order of III → II → I, increasing tendency in order of III ′ → II ′ = I Ratio L / B: Same as III = II = I, increasing in order of III ′ → II ′ → I (4)
Ratio S / A: III = II → I increasing trend, increasing III ′ → II ′ → I increasing ratio L / B: III → II → I increasing, III ′ → II ′ → I increasing

According to the present invention, the adhesive force between the mold and the transfer material changes from small to large to small along a specific direction. Therefore, peeling starts from a region with a small peel force, reaches a peel in a region where the peel force is the largest, and then finishes in a region where the peel force is small, so the sharp increase / decrease in peel stress between each region It is suppressed and the start of peeling is easy, the end of peeling is gentle, and the burden on the mold is reduced.
In the above-described embodiment, the number of regions set along the specific direction in the concavo-convex structure region 13A of the main surface 13 is five, but as described above, the peeling force is small → large → along the specific direction. In order to be able to change to small, it is sufficient that at least three of the specific area and the areas located on both sides thereof exist. However, considering the amount of change in the peel force at the boundary of the region, that is, suppressing the increase in load speed, the peel force is small → medium, medium → large rather than the peel force changing sharply from small to large. It is preferable that the number of regions in a specific direction is large so as to change. Therefore, in the present invention, it is allowed in consideration of restrictions on plural types of uneven structures (required minimum area, peeling direction, etc.), the shape and area of the uneven structure region 13A, and a peeling control function of the imprint apparatus. The number of regions can be increased by appropriately combining within a certain range. For example, when the usable concavo-convex structure is three types of concavo-convex structures R1, R2, and R3, and the concavo-convex structure R1, concavo-convex structure R2, and concavo-convex structure R3 in the descending order of the ratio S / A, as an example, A region in a specific direction is set to five regions III, II, I, II ′, III ′ as in the above example, and a concavo-convex structure R3 is arranged in the regions III and III ′, and the regions II and II ′. The concavo-convex structure R <b> 2 can be arranged in the dent, and the concavo-convex structure R <b> 1 can be arranged in the region I (specific region). As another example, a region in a specific direction is set to nine regions V, IV, III, II, I, II ′, III ′, IV ′, and V ′, and an uneven structure is formed in the regions V and V ′. R3 is disposed, the concavo-convex structure R2 and the concavo-convex structure R3 are disposed in the region IV and the region IV ′, the concavo-convex structure R2 is disposed in the region III and the region III ′, and the concavo-convex structure R1 is disposed in the region II and the region II ′. The uneven structure R3 can be provided, and the uneven structure R1 can be provided in the region I. In this latter example, it is possible to keep the amount of change in the peeling force at the boundary of the region low compared to the former example. In the latter example, in the region IV and the region IV ′ where the uneven structure R2 and the uneven structure R3 are combined, and in the region II and the region II ′ where the uneven structure R1 and the uneven structure R3 are combined, the stress required for peeling in the region It is preferable to arrange two types of uneven regions so as to be uniform.

In the above-described embodiment, the region I is a specific region, and two regions II and III and regions II ′ and III ′ are respectively set on both sides of the region I. The region may not be located at the center of both ends 13a and 13b of the main surface 13, and the number of regions located on both sides of the specific region may not be equal. FIG. 4 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention, and has a plurality of concavo-convex structures along a specific direction (arrow D direction shown in FIG. 4). Regions IV, III, II, I, II ′, and III ′ are located adjacent to each other. In this example, the ratio S / A in each of the regions IV, III, II, I, II ′, and III ′ is directed from the regions IV and III ′ located at both ends of the specific direction D to the region I as the specific region. Preferably, the ratio L / B in each region tends to be the same or increased from the regions IV and III ′ located at both ends of the specific direction D toward the region I as the specific region. Therefore, the following setting example (1 ′) corresponding to the above setting example (1) is possible, and of course within the range satisfying the requirement of the above ratio S / A, preferably the ratio S / A Various areas can be set within a range that satisfies the requirement of the ratio L / B.
(1 ')
Ratio S / A: Increase in order of IV → III → II → I, increase in order of III ′ → II ′ → I L / B: Increase in order of IV → III → II → I, increase in order of III ′ → II ′ → I

<Embodiment 2>
FIG. 5 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. In FIG. 5, an imprint mold 21 has a concavo-convex structure region 23A having a concavo-convex structure to be transferred and a non-concave structure region 23B having no concavo-convex structure on a rectangular main surface 23 of a base material 22. Is set. Note that the non-relief structure region 23B may not exist, and the entire rectangular main surface 23 may be the uneven structure region 23A.
In the concavo-convex structure region 23A of the main surface 23, the concavo-convex structure is formed along a specific direction (in the direction of arrow D shown in FIG. 5) from one corner 23a of the square main surface 23 to the opposite corner 23b. A plurality of regions IV, III, II, I, II ′, III ′, and IV ′ having the following are located adjacent to each other in a grid pattern. In FIG. 5, the region IV is located in the vicinity of the corner 23 a, then, two regions III, three regions II, four regions I are arranged along the specific direction D, and further three regions II ′, two regions III ′ are arranged, and a region IV ′ is located in the vicinity of the corner 23b. In the present invention, the ratio S / A in each of the regions IV, III, II, I, II ′, III ′, and IV ′ is determined as the specific region from the regions IV and IV ′ located at both ends of the specific direction D. The ratio L / B in each region is preferably the same or increasing from the regions IV and IV ′ located at both ends of the specific direction D toward the region I as the specific region. It is in.
The ratio S / A and the ratio L / B in this example are the same as the ratio S / A and the ratio L / B in the first embodiment. In addition, various regions can be set in a range satisfying the requirement of the ratio S / A, preferably in a range satisfying the requirements of the ratio S / A and the ratio L / B.

  Further, in the mold 21 described above, the region I is a specific region, but the specific region may not be located at the center between the corner portion 23a and the corner portion 23b of the main surface 23 facing each other. The number of regions located on both sides of the region may not be equal. Therefore, for example, an area located so as to be adjacent in a grid pattern is located in the vicinity of the corner 23a, and then the area III is located along the specific direction D, and the two areas II and the three areas I (specific areas). ), Four regions II ′, three regions III ′, two regions IV ′ are arranged, and the region V ′ is positioned in the vicinity of the corner 23b. The ratio S / A tends to increase from the regions III and V ′ located at both ends of the specific direction D toward the region I as the specific region. Preferably, the ratio L / B in each region is You may make it become the same or the increasing tendency toward the area | region I as a specific area | region from the area | regions III and V 'located in both ends.

<Embodiment 3>
FIG. 6 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. In FIG. 6, an imprint mold 31 includes a concavo-convex structure region 33 </ b> A having a concavo-convex structure to be transferred to a circular main surface 33 of a substrate 32, and a non-concave structure region 33 </ b> B not having such a concavo-convex structure. Is set. Note that the non-relief structure region 33B may not exist, and the entire circular main surface 33 may be the uneven structure region 33A.

In the mold 31 having such a circular main surface 33, the specific direction can be arbitrarily set. In the illustrated example, the direction of the arrow D is the specific direction, and the specific direction is included in the concavo-convex structure region 33 </ b> A of the main surface 33. A plurality of regions III, II, I, II ′, and III ′ having a concavo-convex structure are adjacent to each other along D. In the present invention, the ratio S / A in each of the regions III, II, I, II ′, and III ′ is directed from the regions III and III ′ located at both ends of the specific direction D to the region I as the specific region. Preferably, the ratio L / B in each region tends to be the same or increases from the regions III and III ′ located at both ends of the specific direction D toward the region I as the specific region.
The ratio S / A and the ratio L / B in this example are the same as the ratio S / A and the ratio L / B in the first embodiment. In addition, various regions can be set in a range that satisfies the requirements of the above ratio S / A, and preferably in a range that satisfies the requirements of the ratio S / A and the ratio L / B.

<Embodiment 4>
FIG. 7 is a plan view corresponding to FIG. 2 showing another embodiment of the imprint mold of the present invention. In FIG. 7, an imprint mold 41 includes a concavo-convex structure region 43 </ b> A having a concavo-convex structure to be transferred to an elliptical main surface 43 of a substrate 42, and a non-concave structure region having no such concavo-convex structure. 43B is set. The non-recessed structure region 43B may not exist, and the entire circular main surface 43 may be the uneven structure region 43A.

In the mold 41 having such an elliptical main surface 43, the major axis direction of the main surface 43 is set as a specific direction, and the concavo-convex structure region 43A of the main surface 43 has a concavo-convex structure along the specific direction D. A plurality of regions III, II, I, II ′, and III ′ are located adjacent to each other. In the present invention, the ratio S / A in each of the regions III, II, I, II ′, and III ′ is directed from the regions III and III ′ located at both ends of the specific direction D to the region I as the specific region. Preferably, the ratio L / B in each region tends to be the same or increases from the regions III and III ′ located at both ends of the specific direction D toward the region I as the specific region.
The ratio S / A and the ratio L / B in this example are the same as the ratio S / A and the ratio L / B in the first embodiment. In addition, various regions can be set in a range that satisfies the requirements of the above ratio S / A, and preferably in a range that satisfies the requirements of the ratio S / A and the ratio L / B.

<Embodiment 5>
FIG. 8 is a plan view corresponding to FIG. 2, showing another embodiment of the imprint mold of the present invention. In FIG. 8, an imprint mold 51 includes an annular base material 52 having an opening 52 a at the center, and an uneven structure region having an uneven structure to be transferred to the annular main surface 53 of the base material 52. 53A and a non-concave structure region 53B that does not have such an uneven structure are set. The non-recessed structure region 53B does not exist, and the entire region of the circular main surface 53 may be the uneven structure region 53A.

In the mold 51 having such an annular main surface 53, the direction from the outer edge 53a of the main surface 53 toward the inner edge 53b on the opening 52a side is a specific direction, and the uneven structure region 53A of the main surface 53 has this A plurality of regions III, II, I, II ′, and III ′ having a concavo-convex structure are positioned along the specific direction D so as to be concentrically adjacent to each other. In the present invention, the ratio S / A in each of the regions III, II, I, II ′, and III ′ is directed from the regions III and III ′ located at both ends of the specific direction D to the region I as the specific region. Preferably, the ratio L / B in each region tends to be the same or increases from the regions III and III ′ located at both ends of the specific direction D toward the region I as the specific region.
The ratio S / A and the ratio L / B in this example are the same as the ratio S / A and the ratio L / B in the first embodiment. In addition, various regions can be set in a range that satisfies the requirements of the above ratio S / A, and preferably in a range that satisfies the requirements of the ratio S / A and the ratio L / B.

The imprint molds 11, 21, 31, 41, 51 of the present invention as described above are arranged in each region so that the adhesion force with the transfer material changes from small to large to small along a specific direction. It is installed. Therefore, peeling starts from a region with a small peel force, reaches a peel in a region where the peel force is the largest, and then finishes in a region where the peel force is small, so the sharp increase / decrease in peel stress between each region It is suppressed and the start of peeling is easy, the end of peeling is gentle, and the burden on the mold is reduced.
The material of the imprint molds 11, 21, 31, 41, 51 of the present invention can be selected as appropriate. When the transfer material is photocurable, the irradiation light for curing them is used. For example, glass such as quartz glass, silicate glass, calcium fluoride, magnesium fluoride, acrylic glass, sapphire, gallium nitride, polycarbonate, polystyrene A resin such as acrylic or polypropylene, or an arbitrary laminated material thereof can be used. In addition, when the transfer material to be used is not photo-curable, or when it is possible to irradiate light for curing the transfer material from the transfer material side, the mold may not be a light-transmitting material. In addition to these materials, for example, metals such as silicon, nickel, titanium, and aluminum, alloys thereof, oxides, nitrides, or any laminated material thereof can be used. The mold may have a release agent layer on the main surface.

  The thicknesses of the molds 11, 21, 31, 41, 51 can be set in consideration of the shape of the concavo-convex structure provided on the main surface, the strength of the base material, suitability for handling, etc., for example, in the range of about 300 μm to 10 mm. It can be set appropriately. The mold may have a so-called mesa structure in which the main surface having a concavo-convex structure has a convex structure with one step or two or more steps with respect to the surrounding area.

<Embodiment 6>
FIG. 9 is a perspective view showing another embodiment of the imprint mold of the present invention, and FIG. 10 is a cross-sectional view perpendicular to the rotation axis of the mold shown in FIG. 9 and 10, an imprint mold 61 includes a cylindrical base member 62 including a cylindrical portion 64 and a pattern portion 65 disposed on the outer peripheral surface of the cylindrical portion 64. A concavo-convex structure region 63A having a concavo-convex structure to be transferred to the peripheral surface 63 (pattern portion 65) 62 and a non-concave structure region 63B not having such a concavo-convex structure are set. The non-recessed structure region 63B may not exist, and the entire surface 63 may be the uneven structure region 63A.

  In the mold 61, a plurality of regions IV, III, II, I, II ′, III ′, and IV ′ having a concavo-convex structure are adjacent to the concavo-convex structure region 63A of the peripheral surface 63 (pattern portion 65) of the base material 62. Is located. These regions are arranged along the circumferential direction from one base line portion 63 a orthogonal to the circumferential direction of the base material 62. In the present invention, the ratio S / A of the measured surface area S of the area to the area A in each of the areas IV, III, II, I, II ′, III ′, and IV ′ is such that the baseline portion 63a is sandwiched therebetween. The adjacent regions IV and IV ′ tend to increase toward a specific region along the circumferential direction. Preferably, the ratio L / B of the measured length L of the region to the region length B in the circumferential direction in each region is along the circumferential direction from adjacent regions IV and IV ′ so as to sandwich the base line part 63a. Tend to be the same or increase toward a specific area. In the illustrated example, the region I is a specific region, and this region I is in a position facing the base line part 63a in the diameter direction. In the present invention, various regions can be set within a range that satisfies the above-described requirements of the ratio S / A, preferably within a range that satisfies the requirements of the ratio S / A and the ratio L / B. Settings like (d) are possible.

(I)
Ratio S / A: Increase in order of IV → III → II → I, increase in order of IV ′ → III ′ → II ′ → I Ratio L / B: Increase in order of IV → III → II → I, IV ′ → III ′ → II ′ → Increase in order of I (b)
Ratio S / A: Increase in order of IV → III → II → I, increase in order of IV ′ → III ′ → II ′ → I Ratio L / B: Same (IV = III = II = I = II ′ = III ′ = IV ′ )
(C)
Ratio S / A: Increase in order of IV → III → II → I, increase in order of IV ′ → III ′ → II ′ → I Ratio L / B: Same as IV = III = II = I, IV ′ → III ′ → II ′ → Increase in order of I (D)
Ratio S / A: IV → III → II → I increasing, IV ′ → III ′ = II ′ → I increasing tendency Ratio L / B: IV → III = II → I increasing tendency, IV ′ → III ′ → Increase in order of II ′ → I

The ratio S / A and the ratio L / B are the same as the ratio S / A and the ratio L / B in the molds 11, 21, 31, 41, 51 described above. Therefore, in the ratio S / A, the area A is determined for each of the set regions IV, III, II, I, II ′, III ′, and IV ′. For example, when the length in the axial direction of the concavo-convex structure region 63A of the base material 62 is 30 mm and the length in the circumferential direction of the region is 6 mm, the area A of the region is 180 mm ² . The areas A in the regions IV, III, II, I, II ′, III ′, and IV ′ may be the same or different. On the other hand, the ratio S / A is calculated by measuring the measured surface area S for each region.
The ratio L / B determines the region length B in the circumferential direction for each of the set regions IV, III, II, I, II ′, III ′, and IV ′. In the above example, the region length B is 6 mm. The region length B in the regions IV, III, II, I, II ′, III ′, and IV ′ may be the same or different. Further, the ratio L / B is calculated by measuring the actual measurement length L for each region.

  As in the case shown in FIG. 3C, the concavo-convex structure has protrusions or recesses that are isolated from each other, and the actual measurement length L in the circumferential direction is measured depending on the measurement site. The average value is taken as the actual measurement length L. Further, for example, when the region length B in the circumferential direction is different depending on the part in one region, if the calculated ratio L / B is constant, this is adopted, and the calculated ratio L / B is adopted. When there is a fluctuation, the average value is the ratio L / B. The average value of the actual measurement length L and the average value in the case of the ratio L / B are obtained by measurement at a plurality of measurement sites over the entire width direction (direction orthogonal to the specific direction D) of the region to be measured. .

  In such an imprint mold 61 of the present invention, each region has an adhesive force with a transfer material that changes from the base line part 63a in the circumferential direction from small to large to small and returns to the base line part 63a. Is arranged. Therefore, when the pressing of the rotating mold and the transfer material starts from the base line part, the pressing starts from the region where the peeling force after pressing is small, and the peeling force after the pressing reaches the region where the peeling force is the largest. Then, since the peeling is finished in a region where the peeling force after pressing is small, a sharp increase / decrease in the peeling stress between the regions is suppressed, and the start of peeling is easy and the end of peeling is gentle. This also reduces the burden on the mold.

  The cylindrical portion 64 constituting the substrate 62 of the imprint mold 61 of the present invention supports the pattern portion 65, and the material thereof can be appropriately selected. For example, aluminum, titanium, Metals such as nickel, and alloys, oxides, and nitrides thereof, and resins such as polycarbonate, polystyrene, acrylic, and polypropylene, quartz glass, silicate glass, calcium fluoride, magnesium fluoride, and acrylic glass Glasses or these arbitrary laminated materials can be used. Moreover, the pattern part 65 which comprises the base material 62 is formed with a plurality of regions having a concavo-convex structure, and the material is, for example, resin such as aluminum, titanium, and further polycarbonate, polystyrene, acrylic, polypropylene, etc. Or these arbitrary laminated materials can be used. Also, on the premise of reducing the thickness so that it can be bent into a cylindrical shape, glass such as quartz glass, silicate glass, calcium fluoride, magnesium fluoride, acrylic glass, silicon, sapphire, gallium nitride, etc. Can be used. Further, the base material 62 is obtained by adhering a single pattern portion 65 formed with all the regions IV, III, II, I, II ′, III ′, and IV ′ in the above example to the cylindrical portion 64. In addition, a plurality of pattern portions 65 in which desired regions of regions IV, III, II, I, II ′, III ′, and IV ′ in the above example are formed are attached to the cylindrical portion 64. There may be.

  In the mold 61 described above, the number of regions is seven. However, in the present invention, there is no particular limitation as long as there are three or more regions in the circumferential direction of the peripheral surface 63. Further, the region I which is a specific region is located at a position facing the base line part 63a in the diameter direction of the base material 62, and three areas II, III, IV are respectively provided between the base line part 63a in the circumferential direction on both sides thereof. Regions II ′, III ′, and IV ′ are set. However, in the present invention, the specific region does not have to exist at a position facing the base line part 63a in the diameter direction of the base material 62, and between the base line part 63a in the circumferential direction on both sides of the specific area. The number of located regions may not be equal.

  The above-described embodiments of the mold for imprint are examples, and the present invention is not limited to these embodiments. For example, in the above-described embodiment, the region is divided only along the specific direction or the circumferential direction, and the ratio S / A is the same in the specific direction or the direction orthogonal to the circumferential direction in each region, Although the peeling force is the same, the region may be divided into a specific direction or a direction orthogonal to the circumferential direction. In this case, the ratio S / A in a specific direction or a direction orthogonal to the circumferential direction in each region does not need to be uniform. However, it is necessary to set the ratio S / A so as to match the above-described principle with respect to a specific direction. The same applies to the ratio L / B. That is, the principles of the peel force, ratio S / A, and ratio L / B are the same as those of the other embodiments for a specific direction, but it is necessary to follow this principle for a direction perpendicular to the specific direction. For example, regions having different ratios S / A may be arranged, or the lengths of the respective regions in a specific direction may be different.

[Method for forming fine structure]
The fine structure forming method of the present invention uses the above-described imprint mold of the present invention to form a transfer material having a fine structure on a substrate by the imprint method.

<Embodiment A>
FIG. 11 is a process diagram for explaining an embodiment of the fine structure forming method of the present invention. In this example of the forming method, the above-described imprint mold 11 of the present invention is used, and has a pressing process, a curing process, and a peeling process. In FIG. 11, uniform fine unevenness is shown in the uneven structure region 13A of the main surface 13 of the mold 11, but this shows the uneven structure for convenience, and as described above, the mold 11 Is provided with an optimum concavo-convex structure in each of the regions III, II, I, II ′ and III ′.

(Pushing process)
First, the transfer material 3 is supplied to one surface 1a of the substrate 1 (FIG. 11A), the mold 11 and the substrate 1 are brought close to each other, and the transfer material is placed between the main surface 13 of the mold 11 and the substrate 1. 3 is interposed (FIG. 11B).
The substrate 1 to be used is, for example, a glass such as quartz, soda lime glass, borosilicate glass, a semiconductor such as silicon or gallium nitride, a resin substrate such as polycarbonate, polypropylene, or polyethylene, a metal substrate, sapphire, or these materials. It may be a composite substrate made of any combination. Further, the base body 1 is not necessarily flat and may have a structure in advance. For example, a desired pattern structure such as a fine wiring used for a semiconductor or a display, a photonic crystal structure, an optical waveguide, or an optical structure such as holography may be formed.

  Moreover, the transfer material 3 to be used may be a material having fluidity that can be imprinted, and examples thereof include a resin such as a photocurable resin, a thermoplastic resin, and a thermosetting resin. For example, inorganic materials such as quartz, soda lime glass, and metal ion-containing glass can also be used as a transfer material because they have fluidity when heated. Furthermore, it is also possible to use a mixture of an inorganic substance and an organic substance. For example, a material containing silsesquioxane as a main component can be regarded as a thermosetting material or a photocurable resin depending on the contained material. Since silsesquioxane has a Si—O—Si skeleton, it can be classified as an inorganic substance. Moreover, since it can be made to have fluidity and can be cured by heat, it can be used in almost the same manner as a thermosetting resin. On the other hand, by having a photopolymerizable group such as an oxetanyl group or an acrylic group, it can be cured by light, and in this case, it can also be used as a photocurable resin. Such a transfer material 3 can be supplied onto the substrate 1 as droplets using an ink jet, a dispenser or the like, as shown in the drawing, and can be applied as a coating film on the substrate 1 using a spin coating method or the like. You may supply.

(Curing process)
Next, the transfer material 3 is cured with the transfer material 3 interposed between the main surface 13 of the mold 11 and the substrate 1. The transfer material 3 can be cured by light irradiation from the mold 11 side when the transfer material 3 is photocurable and the mold 11 can transmit irradiation light for curing them. When the substrate 1 can transmit light, light irradiation may be performed from the substrate 1 side, and light irradiation may be performed from both the mold 11 side and the substrate 1 side. When the transfer material 3 is thermosetting or thermoplastic, the transfer material 3 can be subjected to heat treatment or cooling (cooling) treatment, respectively.

(Peeling process)
Next, by applying a peeling force so as to widen the gap distance between the substrate 1 and the mold 11 along the specific direction D of the mold 11 (the direction of the arrow D shown in FIG. 11C), The transfer material 3 ′ and the mold 11 are peeled off (FIG. 11C). Such peeling from the specific direction D can be performed, for example, by applying a peeling force F to one end side 13a side of the main surface 13 of the mold 11. At this time, a force pressing the mold 11 against the transfer material 3 ′ after curing is applied to the other end side 13 b of the main surface 13 of the mold 11, and the peeling gradually approaches the end side 13 b direction. You may make it cancel | release before this pressing force inhibits peeling. In the mold 11, as described above, a direction from one end side 13 a to the other end side 13 b of the main surface 13 of the substrate 12 is defined as a specific direction D, and a plurality of concavo-convex structures are formed along the specific direction D. The regions III, II, I, II ′, and III ′ are arranged adjacent to each other. Therefore, by peeling from such a specific direction D, peeling is started from a region having a small peeling force, leading to peeling of a region having the largest peeling force, and thereafter, peeling is terminated in a region where the peeling force is small, A steep increase / decrease in peel stress between regions is suppressed.

As a result, a transfer material having a fine structure is formed on the substrate, and the formed fine structure has reduced generation of defects, and also reduces the burden on the mold. Further, the fine structure can be formed in the same manner as described above by using the above-described imprint molds 21, 31, 41 of the present invention.
In this example, the substrate 1 has a flat plate shape. However, the present invention is not limited to this, and the substrate 1 has a cylindrical shape and moves relative to the mold 11 while rotating (in the above-described specific direction D). The base 1 is a continuous body that is transported by a roller, and the mold 11 moves on the roller in accordance with the transport speed of the base 1 (moving in the specific direction D). Good. In such a form, the contact time between the transfer material 3 and the mold 11 is short, and the transfer material 3 is peeled off from the mold 11 in an uncured state. However, in the mold 11 of the present invention, the peeling in the specific direction D is not performed. A steep increase / decrease in the peeling stress between the regions is suppressed, the peeling from the uncured transfer material 3 is surely performed, and then the transfer material 3 is cured to form a fine structure.

<Embodiment B>
FIG. 12 is a process diagram for explaining another embodiment of the fine structure forming method of the present invention. In this example of the forming method, the above-described imprint mold 51 of the present invention is used, and has a pressing step, a curing step, and a peeling step. In FIG. 12, uniform fine unevenness is shown in the uneven structure region 53A of the main surface 53 of the mold 51, but this shows the uneven structure for convenience, and as described above, the mold 51 Is provided with an optimum concavo-convex structure in each of the regions III, II, I, II ′ and III ′.

(Pushing process)
First, the transfer material 3 is supplied to one surface 1a of the substrate 1 (FIG. 12A), the mold 51 and the substrate 1 are brought close to each other, and the transfer material is placed between the main surface 53 of the mold 51 and the substrate 1. 3 is interposed (FIG. 12B). The substrate 1 to be used can be the same as the substrate described in the above-described embodiment A except for a cylindrical shape or a continuous body. The transfer material 3 can also be the same as in the above-described embodiment A.

(Curing process)
Next, the transfer material 3 is cured with the transfer material 3 interposed between the main surface 53 of the mold 51 and the substrate 1. The transfer material 3 can be cured in the same manner as in the above-described embodiment A.

(Peeling process)
Next, by applying a peeling force so as to increase the gap distance between the substrate 1 and the mold 51 along the specific direction D of the mold 51 (the direction of the arrow D shown in FIG. 12C), The transfer material 3 ′ and the mold 51 are peeled off (FIG. 12C). Such peeling from the specific direction D can be performed by, for example, applying the peeling force F evenly to the outer edge portion 53 a of the main surface 53 of the mold 51. At this time, a force pressing the mold 51 against the cured transfer material 3 ′ is applied to the inner edge 53b of the mold 51 on the opening 52a side, and the peeling gradually approaches the opening 52a. You may make it cancel | release before the applied force inhibits peeling. In the mold 51, as described above, the direction from the outer edge 53a of the main surface 53 toward the inner edge 53b on the opening 52a side is defined as a specific direction D, and a plurality of regions III having a concavo-convex structure along the specific direction D , II, I, II ′, III ′ are arranged so as to be concentrically adjacent to each other. By such peeling from the specific direction D, peeling is started from a region having a small peeling force, leading to peeling of a region having the largest peeling force, and then peeling is finished in a region where the peeling force is small. A steep increase / decrease in the peeling stress at is suppressed.
As a result, a transfer material having a fine structure is formed on the substrate, and the formed fine structure has reduced generation of defects, and also reduces the burden on the mold.

<Embodiment C>
FIG. 13 is a process diagram for explaining another embodiment of the fine structure forming method of the present invention. In this example of the forming method, the above-described imprint mold 61 of the present invention is used, and has a pressing step, a transfer / peeling step, and a curing step. In FIG. 13, uniform fine unevenness is described in the uneven structure region of the peripheral surface 63 of the mold 61, but this shows the uneven structure for convenience, and as described above, the mold 61 is Each region IV, III, II, I, II ′, III ′, IV ′ has an optimum uneven structure.

(Pushing process)
First, the transfer material 7 is supplied to one surface 5a of the base 5 (FIG. 13A), the mold 61 and the base 1 are brought close to each other, and the base line portion 63a of the mold 61 is pressed against the transfer material 7 (FIG. 13 (B)).
The substrate 5 to be used can be the same as the substrate 1 of the above-described embodiment A. In the illustrated example, the substrate 1 is plate-shaped, but may be cylindrical, continuous, or the like. The transfer material 7 can be the same as the transfer material 3 of the above-described embodiment A, and the supply of the transfer material 7 onto the substrate 5 is supplied as a coating film using a spin coat method or the like.

(Transfer / curing / peeling process)
Next, while the mold 61 is rotated once in the circumferential direction, the transfer substrate 7 is cured in contact with the mold 61, the cured transfer material 7 and the mold 61 are peeled off, and the transfer material 7 is molded. The uneven structure 61 is transferred (FIG. 13C). FIG. 13C shows a state where the mold 61 is half rotated. In the mold 61, as described above, a plurality of regions IV, III, II, I, II ′, III ′, and IV ′ having a concavo-convex structure are arranged along the circumferential direction so as to be adjacent to each other. In the pressing step, the base line portion 63a of the mold 61 is pressed against the transfer material 7. Therefore, the rotation of the mold 61 starting from the base line portion 63a has a small peeling force after pressing. The pressing starts from the point where the peeling force after pressing reaches a region where the peeling force is the largest, and then the region where the peeling force after pressing reaches a small region ends one rotation. Therefore, a steep increase / decrease in peeling stress between the regions is suppressed, the uneven structure of the mold 61 is stably transferred to the transfer material 7, and the burden on the mold 61 is reduced. Curing of the transfer material 7 can be the same as in the above-described embodiment A.
As a result, a transfer material having a fine structure is formed on the substrate, the formed fine structure has reduced generation of defects, and the burden on the mold is reduced.

Here, in the embodiment shown in FIG. 13, the transfer base material 7 is required to have good followability with respect to the concavo-convex structure of the cylindrical mold 61 and to have a high curing speed. On the other hand, when the followability of the transfer substrate 7 to the concavo-convex structure of the cylindrical mold 61 is poor and it takes time to follow the concavo-convex structure after the mold 61 is pressed, for example, the rotational speed of the mold 11 Or the mold 61 is not a cylinder but a belt-like structure, and the contact time with the transfer material 7 needs to be increased. Alternatively, when the substrate 5 and the transfer material 7 are materials that allow bending, the conveyance path of the substrate 5 is not in line contact with the cylindrical mold 61 but in surface contact with the cylindrical mold 61. It is also preferable to bend along 61.
Further, even if the transfer material 7 is not completely cured, if the uneven structure transferred from the mold 61 can be maintained to some extent, after the transfer material 7 and the mold 61 are peeled, You may perform a hardening process. In this case, since the peeling stress is further reduced, the burden on the mold is also reduced.

In the above example, the mold 61 is rotated once. However, in the present invention, the mold 61 can be rotated twice or more. Even in this case, the base line portion 63a of the mold 61 is transferred to the transfer material 7. Since the rotation starts and ends from the pressed state, a steep increase / decrease in peeling stress between each region is suppressed, and the uneven structure of the mold 61 is stably transferred to the transfer material 7 by n rotation. Also, the burden on the mold 61 is reduced.
The above-described embodiments of the fine structure forming method are examples, and the present invention is not limited to these embodiments.

  It can be used for formation of various fine structures by the imprint method, fine processing, and the like.

11, 21, 31, 41, 51, 61 ... Mold 12, 22, 32, 42, 52, 62 ... Base material 13, 23, 33, 43, 53 ... Main surface 63 ... Peripheral surface 1,5 ... Base material 3, 7. Transfer material

Claims (13)

A mold having a concavo-convex structure on a main surface of a substrate, for transferring the concavo-convex structure to the transfer material by peeling the transfer material from the mold after the concavo-convex structure is filled with a transfer material and cured. In imprint molds,
And specific direction peeling direction of the transfer substrate and the mold, on the main surface of the substrate, positioned so that a plurality of regions are adjacent along the specific direction having an uneven structure,
A plurality of the regions are positioned such that the stress required for peeling the transfer material for each region tends to increase from the region located at both ends in the specific direction toward the specific region. mold.   The ratio S / A of the measured surface area S of the region to the area A of each of the plurality of regions tends to increase from the region located at both ends in the specific direction toward the specific region. The mold for imprints according to 1.   The ratio L / B of the actually measured length L to the region length B in the specific direction in each region tends to be the same or increasing from the region located at both ends of the specific direction toward the specific region. Or the mold for imprint of Claim 2.   The main surface is a square, and the specific direction is a direction from one opposite end of the main surface to the other end, or a direction from one opposite corner of the main surface to the other corner. The imprint mold according to claim 1, wherein the imprint mold is provided.   The main surface is a regular N-gon (N is an integer of 5 or more), and the specific direction is a direction from one opposite end of the main surface to the other end, or one opposite corner of the main surface. The in-direction according to any one of claims 1 to 3, wherein the inward direction is a direction from one portion toward the other end side, or a direction from one opposite corner portion of the main surface to the other corner portion. Mold for printing.   The imprint mold according to any one of claims 1 to 3, wherein the main surface is circular and the specific direction is arbitrarily set.   The imprint mold according to any one of claims 1 to 3, wherein the main surface is elliptical, and the specific direction is an elliptical major axis direction of the main surface.   The main surface is an annular shape having an opening, and the specific direction is a direction from an outer edge of the main surface toward an inner edge on the opening side. The mold for imprint as described. A mold having a concavo-convex structure on a peripheral surface of a cylindrical base material, the transfer structure is filled with a transfer material and cured, and then the transfer material is peeled off from the mold to transfer the concavo-convex structure to the transfer material. In an imprint mold for
The circumferential surface of the cylindrical base material is positioned so that a plurality of regions having a concavo-convex structure are adjacent to each other along the circumferential direction from one baseline portion perpendicular to the circumferential direction of the circumferential surface,
The plurality of regions are positioned so that the stress required for peeling the transfer material for each region tends to increase from the adjacent region to the specific region along the circumferential direction so as to sandwich the baseline portion. Characteristic mold for imprint.   The ratio S / A of the measured surface area S of the region to the area A in each region of the plurality of regions tends to increase from the adjacent region to the specific region along the circumferential direction so as to sandwich the baseline portion. The mold for imprinting according to claim 9.   The ratio L / B of the actually measured length L to the circumferential region length B in each region has the same or increasing tendency from the adjacent region to the specific region along the circumferential direction so as to sandwich the baseline portion. The mold for imprinting according to claim 9 or 10, characterized by the above. A pressing step of interposing a transfer material between the main surface of the imprint mold according to any one of claims 1 to 8 and the substrate;
A curing step for curing the transfer material;
A peeling step of peeling off the transfer material after curing and the mold,
In the peeling step, a peeling force is applied so as to widen a gap distance between the base and the mold along the specific direction of the mold. A pressing step of pressing the transfer material disposed on the substrate and the cylindrical imprint mold according to claim 9,
While the mold is rotated n times in the circumferential direction (n is an integer of 1 or more), the transfer substrate is cured in contact with the mold, and the cured transfer material and the mold are peeled off, A transfer / curing / peeling step for transferring the concavo-convex structure of the mold to the transfer material,
In the pressing step, the base portion of the mold is pressed against a transfer material, and in the transfer / curing / peeling step, the rotation is stopped while the base portion of the mold is in contact with the transfer material. Method for forming a fine structure.

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