JP5978552B2 - Nanoimprint mold and pattern forming method - Google Patents

Description

  The present invention relates to a nanoimprint mold for transferring and forming a desired line, a pattern such as a pattern (hereinafter also referred to as a pattern in the present invention), and a surface shape on a workpiece.

In recent years, attention has been focused on nanoimprint technology as a microfabrication technology. The nanoimprint technology is a pattern formation technology that uses a mold member having a fine concavo-convex structure formed on the surface of a substrate and transfers the concavo-convex structure to a workpiece to transfer the fine structure at the same magnification (Patent Document 1).
As one method of the nanoimprint technique, an optical imprint method is known. In this optical imprint method, for example, a photocurable resin layer is formed as a workpiece on the substrate surface, and a mold (mold member) having a desired uneven structure is pressed against the resin layer. In this state, the resin layer is irradiated with light from the mold side to cure the resin layer, and then the mold is separated from the resin layer. As a result, a concavo-convex structure (concave / convex pattern) in which the concavo-convex portion of the mold is inverted can be formed on the resin layer that is a workpiece (Patent Document 2). Such optical imprints are capable of forming nanometer-order fine patterns that are difficult to form with conventional photolithography techniques, and are promising as next-generation lithography techniques.
However, in the optical imprint method, as shown in FIG. 8, when the mold 51 is pressed against the photocurable resin layer 62 disposed as a workpiece on the surface of the substrate 61, excess resin is formed. , It protrudes outside the area in contact with the mold 51 and adheres to the side surface 52 of the mold. The photocurable resin adhering to the side surface 52 is cured simultaneously with the resin at the portion where the uneven structure (uneven pattern) is to be formed by light irradiation. When the mold 51 is released, a frictional force is generated between the cured resin layer 62 and the side surface 52 of the mold 51, and the force required for the release (release force) is not constant and varies. There is a problem that damage is likely to occur when the mold or workpiece is damaged, and particularly when the concavo-convex structure (concave / convex pattern) to be formed is fine.

Moreover, when forming the fine concavo-convex structure which a mold has in several places on a to-be-processed object, pattern formation may be performed by a step and repeat system. When a conventional mold is used, the resin layer outside the portion where the concavo-convex structure is to be formed is exposed by light passing outside the pattern region where the concavo-convex structure is formed, and the region that is cured by one pattern formation is It becomes larger than the pattern area of the mold. On the other hand, if the photocurable resin layer is exposed and cured, pattern formation cannot be performed at that location. For this reason, there has been a problem that the boundary width between regions where adjacent patterns are formed must be set large.
In order to solve such a problem, a mold in which a light shielding member is provided in a portion (non-pattern region) that is not a pattern region has been proposed (Patent Document 3).

US Pat. No. 5,772,905 Special Table 2002-539604 JP 2007-103924 A

In the mold provided with the light shielding member, the light curable resin layer that protrudes to the outside when the mold is pressed is prevented by curing the light shielding member on the side surface of the mold.
However, in such a mold, when pattern formation is performed by the step-and-repeat method, it is possible to prevent the resin in the region before processing from being exposed and cured, but there are the following problems. .
First, when the light shielding by the light shielding member provided on the side surface of the mold is complete, the photo-curing resin layer protruding outside when the mold is pressed is not cured. There is a problem in that the cured resin layer flows and flows into the portion of the concavo-convex structure formed by transfer to cause defects. Further, when the mold is released, there is a problem that an uncured resin layer adheres to the mold as a foreign substance, and the foreign substance causes a defect in the next processing region.

On the other hand, when light shielding by the light shielding member provided on the side surface of the mold is incomplete, and a part of the photo-curing resin layer in a portion contacting the side surface of the mold is cured, the uncured resin is bonded to the cured resin. Due to insufficient force, the uncured resin does not remain on the cured resin side on the substrate, but adheres to the mold side at the time of mold release, resulting in a foreign object and causing defects in the next processing area was there.
This invention is made | formed in view of the above situations, and it aims at providing the mold for nanoimprint excellent in the releasability with the to-be-processed object after an optical imprint.

In order to achieve such an object, the mold for nanoimprinting of the present invention includes a substrate having a base portion and a convex structure portion protruding from one surface of the base portion, and a transfer shape positioned on the upper surface of the convex structure portion. And an inclined portion located in the entire circumferential direction of the side surface of the convex structure portion, and the transfer shape portion includes a flat surface that forms a common surface with the upper surface and a concave portion that is positioned on the flat surface. A flat surface that forms a common surface with the upper surface, a concave plane that is more concave than the upper surface, and a concave portion that is located in the concave plane, a flat surface that forms a common surface with the upper surface, and the upper surface A convex plane in a convex state and a concave portion located in the convex plane, the depth of which is greater than the height of the convex state of the convex plane from the upper surface, and a common surface with the upper surface Any one of the flat surfaces formed, The inclined portion occupies a part in the height direction of the side surface of the convex structure portion, and the start portion of the inclined portion coincides with the flat surface that forms a common surface with the upper surface of the convex structure portion, and excludes the inclined portion. The side surface of the convex structure portion was configured to be perpendicular to the upper surface of the convex structure portion.
As another aspect of the present invention, the inclined portion has a concave shape that is recessed in the inner direction of the convex structure portion.
As another aspect of the present invention, the angle formed by the inclined portion and the upper surface of the convex structure portion is in the range of 10 ° to 60 °.
As another aspect of the present invention, the transfer shape portion has a recess, and the height required from the upper surface of the protrusion structure portion to the end portion of the inclined portion is larger than the maximum depth of the recess. did.
As another aspect of the present invention, a configuration is adopted in which the end portion of the inclined portion and the deepest portion of the concave portion are spaced apart by 10 μm or more in the height direction of the convex structure portion.
According to the pattern forming method of the present invention, a photocurable resin droplet is supplied to a substrate, and a photocurable resin layer is formed by bringing any of the above-described nanoimprint molds into contact with the droplet. The step of curing the photocurable resin layer with the mold, and then releasing the cured resin layer and the mold, and bringing the transfer forming portion of the nanoimprint mold into contact with the droplets for photocuring When the resin layer is formed, the photocurable resin layer is controlled so as to come into contact with the inclined portion of the convex structure portion and not to contact the side surface of the convex structure portion excluding the inclined portion. The configuration.
As another aspect of the present invention, an inclined portion of the convex structure portion is in contact with the photocurable resin layer, and side surfaces of the convex structure portion excluding the inclined portion are not in contact with the photocurable resin layer. The convex structure portion of the mold was pushed into the photocurable resin layer while adjusting the thickness.

  In the present invention described above, when the light irradiation is completed at the time of nanoimprinting and the nanoimprint mold is released from the workpiece, the frictional force generated between the cured workpiece and the side surface of the nanoimprint mold is convex. It is reduced by the inclined part located on the side of the structure part, and the fluctuation of the force required for mold release (mold release force) is suppressed, which prevents damage to the nanoimprint mold and work piece, and the fine uneven structure There is an effect that the (uneven pattern) can be stably formed.

It is a top view which shows one Embodiment of the mold for nanoimprint of this invention. It is sectional drawing in the AA line of the mold for nanoimprint shown by FIG. It is a partial expanded sectional view for demonstrating the inclination part of the mold for nanoimprint shown by FIG. 1 and FIG. It is a figure for demonstrating the other example of the inclination part of the mold for nanoimprint. It is a figure for demonstrating other embodiment of the mold for nanoimprint of this invention. It is a figure for demonstrating an example of the pattern formation by the nanoimprint by the imprint apparatus using the mold for nanoimprint shown by FIG. 1 and FIG. It is a figure for demonstrating the other example of the transcription | transfer shape part of the mold for nanoimprint of this invention. It is a figure which shows an example of the mold for conventional nanoimprint.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of a nanoimprint mold of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of the nanoimprint mold shown in FIG. A mold 1 shown in FIG. 1 is a nano-imprint mold having a mesa structure, a transparent base material 2 having a base portion 3 and a convex structure portion 4 protruding from one surface of the base portion 3, and a convex structure portion 4. The transfer shape portion 5 located on the upper surface 4a of the projection structure 4 and the inclined portion 6 (hatched in FIG. 1) are located in the entire peripheral direction of the side surface 4b of the convex structure portion 4. The substrate 2 is defined by a pattern region X, a non-pattern region Y positioned around the pattern region X, and a convex structure region Z. The convex structure portion region Z indicates a region (maximum region) where the convex structure portion 4 is located and the mold 1 may come into contact with the workpiece during nanoimprinting. The transfer shape portion 5 is located in the pattern region X, and the inclined portion 6 is located in the convex structure portion region Z around the pattern region X. In FIG. 1, a later-described concave portion 5b constituting the transfer shape portion 5 located on the upper surface 4a of the convex structure portion 4 is omitted.
The base material 2 constituting the mold 1 of the present invention is a transparent base material capable of transmitting irradiation light for curing the workpiece. As a material of such a base material 2, for example, quartz glass, silicate glass, calcium fluoride, magnesium fluoride, acrylic glass, or an arbitrary laminated material thereof can be used. Furthermore, the mold for nanoimprinting of the present invention has the same effect in thermal nanoimprinting, and as a material for the substrate 2, a metal such as copper, nickel, iron, or an alloy thereof, or silicon can be used. Moreover, the thickness of the base material 2 can be set in consideration of the material of the workpiece, the shape of the convex structure portion 4, the strength of the base material, the suitability for handling, and the like. For example, the thickness is appropriately set in the range of about 300 μm to 10 mm. can do.

In the example shown in FIG. 2, the transfer shape portion 5 located on the upper surface 4a of the convex structure portion 4 is composed of a flat surface 5a that forms a common surface with the upper surface 4a and a concave portion 5b that is located on the flat surface 5a. . The concave portion 5b is a concave portion corresponding to a shape in which the irregularities of the pattern shape to be formed by nanoimprint are inverted, and can be set as appropriate, and can be formed by etching or the like.
The inclined portion 6 located on the side surface 4b of the convex structure portion 4 is formed between the cured workpiece and the side surface of the mold 1 when the light irradiation is completed at the time of nanoimprinting and the mold 1 is released from the workpiece. This is to reduce the generated frictional force and suppress the fluctuation of the force required for mold release (mold release force) to prevent the mold and workpiece from being damaged. That is, the work piece that has become surplus by pressing the mold 1 protrudes outside the pattern formation region X (the convex structure portion region Z around the pattern region X) and adheres to the side surface 4 b of the convex structure portion 4. To do. The workpiece attached to the side surface 4b of the convex structure 4 is cured simultaneously with the workpiece located in the pattern region X. For this reason, when the mold 1 is released, a frictional force is generated between the cured workpiece and the side surface 4 b of the convex structure portion 4, and this frictional force is reduced by the inclined portion 6.

  FIG. 3 is a partially enlarged cross-sectional view for explaining the inclined portion 6 of the nanoimprint mold 1 shown in FIGS. 1 and 2. In the illustrated example, the inclined portion 6 has a start portion 6a that coincides with the upper surface 4a of the convex structure portion 4 and forms a certain angle θ with respect to the upper surface 4a. Also, the height direction of the side surface 4b of the convex structure portion 4 Occupies a part of (direction indicated by arrow a). Therefore, the side surface 4b of the convex structure portion 4 is composed of the inclined portion 6 and a side surface 4b 'perpendicular to the upper surface 4a of the convex structure portion 4 (θ = 90 °). Here, when the entire side surface 4b of the convex structure portion 4 is perpendicular (θ = 90 °) to the upper surface 4a of the convex structure portion 4 (see the mold 51 in FIG. 8), the cured workpiece If the frictional force generated between the convex portion 4 and the side surface 4b of the convex structure 4 is F, the frictional force generated between the cured workpiece and the inclined portion 6 is Fsinθ. For this reason, it is preferable that the constant angle θ formed by the inclined portion 6 with respect to the upper surface 4a of the convex structure portion 4 is smaller. The width W of the convex structure portion region Z existing outside the pattern region X, the convex structure portion 4 can be appropriately set in consideration of the height h required from the upper surface 4a to the end portion 6b of the inclined portion 6, and the angle θ is, for example, in the range of 10 ° to 60 °. it can. When the angle θ formed by the inclined portion 6 with respect to the upper surface 4a of the convex structure portion 4 exceeds 60 °, when the nanoimprint mold is released from the workpiece, the cured workpiece and the side surface of the nanoimprint mold It is not preferable because the frictional force generated during the process is insufficiently reduced, the force required for mold release (mold release force) fluctuates, and the nanoimprint mold 1 and the workpiece may be damaged. . Also, if it is less than 10 °, it is not preferred because it is easily affected by the parallelism of the stage in the nanoimprint apparatus and the parallelism of the mold for nanoimprint, and the reduction of the frictional force that is the effect of the present invention becomes insufficient.

Here, the height h required from the upper surface 4a of the convex structure portion 4 to the end portion 6b of the inclined portion 6 is set according to the height of the workpiece protruding from the pattern region X, and is applied to the workpiece. In addition to the pressing amount (indentation depth) of the mold 1, the fluidity of the workpiece, the viscoelasticity, etc., the wettability with the mold is determined. The range of possible values of the height h will be examined in detail.
First, the upper limit of the height h is equal to the height H of the convex structure portion 4. This is because the frictional force can be reduced when the workpiece is in contact with only the inclined portion 6. When the height of the workpiece that protrudes from the pattern region X exceeds the upper limit (height H) of the height h, the frictional force cannot be controlled. In other words, even if the work piece protrudes from the pattern region X, it only needs to be in contact with the inclined portion 6.

  Next, the lower limit of the height h is examined based on the above concept. When the transfer shape portion 5 having the recess 5b of the mold 1 comes into contact with the workpiece, the workpiece may enter the recess 5b due to a capillary phenomenon. However, in the inclined portion 6, a meniscus is formed due to the wettability between the mold and the workpiece, and this causes the workpiece to protrude. At this time, since the workpiece protrudes to the inclined portion 6, the height of the protruding workpiece is lower than the depth d of the recess 5b, and is substantially the same as the smooth surface. Therefore, in order to obtain the effect of reducing the frictional force by the inclined portion 6, it is necessary not only to bring the mold into contact with the workpiece, but also to push the mold into the workpiece by applying a very slight force. However, in this case, as described below, it is difficult to always control the amount of protrusion of the workpiece to be constant due to the drop amount of the resin and the drive controllability of the nanoimprint apparatus. That is, for example, when the dropping amount of the resin droplet supplied to the substrate as a workpiece is 10 pl and the diameter of the droplet is 20 to 30 μm, such a droplet size is a pattern to be obtained by nanoimprinting. Even if the size is about 100 nm, it is a very large number. As described above, when the resin is filled in the concave portion 5b of the mold using droplets having a diameter larger than the pattern size and the amount of the protruding resin is controlled, the mold and the substrate are parallel in the nanoimprint apparatus. The degree and reproducibility of the indentation amount must be controlled at the nanoscale. Therefore, it is difficult to always control the amount of protrusion of the workpiece to be constant. Rather than controlling these, the height h of the inclined portion of the mold is increased, and a space is provided in the space where the workpiece protrudes. However, it is easy and practically preferable. Here, since the range of the angle θ formed by the inclined portion 6 with respect to the upper surface 4a of the convex structure portion 4 is within the range of 10 ° to 60 ° as described above, the workpiece is spread in the horizontal direction. . Therefore, considering the amount of protrusion of the workpiece, the height h needs to be larger than the maximum depth dmax of the recess 5b.

From the above examination, the relationship of dmax <h ≦ H is established between the height h, the maximum depth d of the concave portion 5b, and the height H of the convex structure portion 4. Further, when spreading the resin protruding in the horizontal direction, it is necessary to sufficiently increase the height h to secure a space where the resin can protrude. Therefore, the height h is preferably set to be 50 times or more of the maximum depth dmax of the recess 5b.
Further, the height h can be set so that the end portion 6b of the inclined portion 6 and the deepest portion of the concave portion 5b are separated by 10 μm or more, preferably 15 μm or more in the height direction of the convex structure portion 4. If the height h is less than the above range, the workpiece 1 is surplus when pressed against the mold 1 and protrudes outside the pattern formation region X (the convex structure region Z around the pattern region X). May be attached to the side surface 4b 'that is perpendicular to the upper surface 4a of the convex structure portion 4 (θ = 90 °) and interferes with the effect of the present invention.
As described above, the inclined portion 6 located in the entire circumferential direction of the side surface 4b of the convex structure portion 4 is formed by polishing the peripheral portion of the convex structure portion 4 by mask etching, lapping, polishing, buffing, or the like. be able to. As described above, when the inclined portion 6 forms a certain angle θ with respect to the upper surface 4a, the workpiece 1 is inclined during the operation of peeling the workpiece from the inclined portion 6 when the mold 1 is released from the workpiece. Since the frictional force acting between the part 6 and the workpiece is constant, variation in the release force is reduced.

In the present invention, the inclined portion 6 is not limited to the shape shown in FIG. 3, and the angle θ formed by the inclined portion 6 with respect to the upper surface 4 a of the convex structure portion 4 may not be constant. . For example, as shown in FIG. 4A, the inclined portion 6 may have a convex shape. In this example, the angle with respect to the upper surface 4a at the portion 6a where the inclined portion 6 starts from the upper surface 4a of the convex structure portion 4 is θ ₁ , and the angle with respect to the upper surface 4a at the end portion 6b of the inclined portion 6 is θ _2. The angle with respect to 4a is gradually increased from the angle θ ₁ to the angle θ ₂ . Also in such an embodiment, the angle of the inclined portion 6 with respect to the upper surface 4a of the convex structure portion 4 can be set similarly to the above example. For example, (θ ₁ + θ ₂ ) / 2 can be 60 ° or less, preferably 45 ° or less, and more preferably, the largest angle θ ₂ can be 45 ° or less.
Further, as shown in FIG. 4B, the inclined portion 6 may be concave. In this example, the angle with respect to the upper surface 4a at the portion 6a where the inclined portion 6 starts from the upper surface 4a of the convex structure portion 4 is θ ₁ , and the angle with respect to the upper surface 4a at the end portion 6b of the inclined portion 6 is θ _2. The angle with respect to 4a is gradually reduced from the angle θ ₁ to the angle θ ₂ . Also in such an aspect, the angle of the inclined part 6 with respect to the upper surface 4a of the convex structure part 4 can be set similarly to the above example. For example, (θ ₁ + θ ₂ ) / 2 can be 60 ° or less, preferably 45 ° or less, and more preferably, the largest angle θ ₁ can be 45 ° or less.

Further, the inclined portion 6 may have a convex shape whose angle changes stepwise or a concave shape, and as an example of this, an example of the convex shape is shown in FIG. As shown in FIG. 4 (C), the angle is theta ₁ with respect to the upper surface 4a of the surface 6A of the inclined section 6 is started from the upper surface 4a of the convex portions 4, the angle surface 6B following the surface 6A is with respect to the upper surface 4a There is a theta _2, a ₃ angle theta with respect to the upper surface 4a of the surface 6C following the surface 6B, the angle with respect to the upper surface 4a is made stepwise increased from the angle theta ₁ to the angle theta _3. Also in such an aspect, the angles of the inclined portions 6A, 6B, 6C with respect to the upper surface 4a of the convex structure portion 4 can be set similarly to the above example. For example, (θ ₁ + θ ₂ + θ ₃ ) / 3 can be 60 ° or less, preferably 45 ° or less, and more preferably, the largest angle θ ₃ can be 45 ° or less.
Thus, the inclined portion 6 having a change in the angle with respect to the upper surface 4a of the convex structure portion 4 can be formed by polishing by, for example, wet etching, lapping, polishing, buffing or the like. Then, as shown in FIGS. 4A and 4C, when the inclined portion 6 has a convex shape, the portion where the peeling between the mold 1 and the work piece occurs is the inclined portion 6. The angle θ decreases from the outside to the inside and approaches the upper surface 4a, stress generation can be suppressed, and damage to the workpiece can be suppressed.

  In addition, the inclined portion 6 occupying the side surface 4b of the convex structure portion 4 is not limited to the form shown in FIGS. 3 and 4A to 4C. For example, as shown in FIG. 5A, the entire surface in the height direction of the side surface 4b of the convex structure portion 4 may be the inclined portion 6 (h = H in FIG. 3). Further, in the case where the convex structure region Z extends over the entire area of the base material 2 (Z = X + Y), as shown in FIG. 5B, the portion 6b where the inclined portion 6 ends is the base material 2 (base 3). ) May be located at the end.

Next, an example of pattern formation by nanoimprinting by an imprinting apparatus using such a nanoimprinting mold 1 will be described with reference to FIG.
As shown in FIG. 6, the convex structure portion 4 of the mold 1 is pushed into a predetermined depth into a photocurable resin layer 22 disposed as a workpiece on the surface of the substrate 21. In this state, the back surface 2b of the mold 1 is irradiated with ultraviolet rays from an illumination optical system (not shown) through the light shielding mask 31, and the resin layer 22 is cured by the ultraviolet rays that have passed through the mold 1. At this time, the resin layer 22 located in the convex structure region Z is cured together with the resin layer 22 located in the pattern region X.
Thereafter, the mold 1 for nanoimprint is released from the resin layer 22, whereby a concavo-convex structure (concave / convex pattern) 23 in which the concave portions 5 b of the mold 1 are inverted is transferred and formed on the resin layer 22 as a workpiece. At the time of this mold release, the cured resin layer 22 located outside the pattern region X is in contact with the inclined portion 6 of the mold 1, so that a mold generated between the cured resin layer 22 and the mold 1 is obtained. The force (friction force) acting parallel to the side surface inclination is reduced, and fluctuations in the force required for mold release (mold release force) are suppressed. Thereby, damage to the nanoimprint mold 1 and the workpiece 22 can be prevented, and a fine uneven structure (uneven pattern) 23 can be stably formed.

  The above-described embodiment is an exemplification, and the present invention is not limited to this. For example, the transfer shape portion 5 located on the upper surface 4a of the convex structure portion 4 is not limited to that shown in FIG. 2, but is a flat surface that forms a common surface with the upper surface 4a, as shown in FIG. 7A. You may comprise the surface 5a, the concave plane 5c, and the recessed part 5b located in this concave plane 5c. Further, as shown in FIG. 7B, a flat surface 5a that forms a common surface with the upper surface 4a, a convex plane 5d, and a concave portion 5b that is located on the convex plane 5d, and FIG. As shown in C), it may be constituted only by a flat surface 5a that forms a common surface with the upper surface 4a.

Next, the present invention will be described in more detail by showing more specific examples.
[Example 1]
Quartz glass (65 mm square) with a thickness of 6.35 mm was prepared as a base material for a mold for nanoimprinting.
Next, an inclined portion as shown in FIG. 5B was formed by buffing the peripheral portion (width of 12.5 mm from the end portion) of the base material. The angle formed by the inclined portion with the upper surface (40 mm square) of the convex structure portion is 60 ° (constant), and the height h from the upper surface of the convex structure portion to the end portion of the inclined portion (see FIG. 5B) is It was 4 mm.

Next, a commercially available photosensitive resist is applied onto the substrate, and the photosensitive resist located on the upper surface of the convex structure portion is exposed and developed by electron beam drawing to form an LS pattern having a pitch of 200 nm and a pattern width of 100 nm. A resist pattern was formed. Using this resist pattern as a mask, the upper surface of the convex structure portion was dry-etched under the following conditions to form a recess having a depth of 100 nm to form a transfer shape portion.
(Dry etching conditions)
Etching gas: CF ₄
・ Gas flow rate: 40sccm
・ Chamber pressure: 4Pa
・ Input RF power: 400W
Thereby, a mold for nanoimprinting as shown in FIG. 5B was obtained.

[Comparative example]
The mesa processing by dry etching is performed on the peripheral part (width of 12.5 mm from the end part) of the nanoimprint mold base material to form a convex structure part (40 mm square) with a height of 15 μm. A nanoimprint mold as shown in FIG. 8 was produced in the same manner as in Example 1 except that the inclined portion was not formed on the outer peripheral portion.

<Evaluation>
Using the nanoimprint mold (Examples and Comparative Examples) produced in this manner, nanoimprinting was performed as follows.
That is, a photocurable resin (PAK-01 manufactured by Toyo Gosei Kogyo Co., Ltd.) is applied on a quartz wafer having a thickness of 625 μm to form a workpiece, and placed on the substrate stage of the imprint apparatus so that the quartz wafer side contacts. did. Next, a mold was pushed into the photocurable resin layer. At this time, the pressing force of the mold to the photocurable resin layer was 1 kN, which was smaller than the height (15 μm) of the convex structure portion in the mold of the comparative example. In this state, 100 mJ / cm ^{2 of} parallel light (ultraviolet light having a peak wavelength of 365 nm) was irradiated from the illumination optical system of the imprint apparatus. Thereby, the photocurable resin layer was cured, and then the pattern was formed by separating the mold.

Such pattern formation is performed 10 times for each mold, and the force (N) required for separating the molds is measured using a load cell built in the nanoimprint apparatus, and the measured value (N) is contacted between the resin and the mold. The release force (MPa) was calculated by dividing by the measured area (mm ² ), and the average value and the fluctuation amount (difference between the maximum value and the minimum value) are shown in Table 1. Moreover, the defect rate was measured about the formed pattern as follows, and the result was shown in Table 1.
(Defect rate measurement)
Observe five patterns for each pattern with an optical microscope, and measure the ratio of the area where pattern defects were confirmed within one observation spot (1.0 mm × 1.0 mm). The average of 100 patterns and a total of 500 spots. Was calculated. Therefore, it means that there are many defects, so that this defect rate is large, and in this invention, it determines with a defect rate being less than 0.1 as a practical use level.

表１に示されるように、実施例のモールドを使用した場合、比較例のモールドを使用した場合に比べて離型力の変動量が少なく、欠陥率が小さいことが確認された。

As shown in Table 1, it was confirmed that when the mold of the example was used, the variation amount of the release force was small and the defect rate was small compared to the case where the mold of the comparative example was used.

  It can be used for microfabrication using nanoimprint technology.

DESCRIPTION OF SYMBOLS 1 ... Nanoimprint mold 2 ... Base material 3 ... Base part 4 ... Convex structure part 4a ... Upper surface 4b ... Side surface 5 ... Transfer shape part 6 ... Inclination part X ... Pattern area Y ... Non-pattern area Z ... Convex structure area

Claims (7)

A base having a base and a convex structure protruding from one surface of the base; a transfer shape positioned on the upper surface of the convex structure; and an inclined portion positioned in the entire circumferential direction of the side surface of the convex structure And comprising
The transfer shape portion includes a flat surface that forms a common surface with the upper surface and a concave portion that is located on the flat surface, a flat surface that forms a common surface with the upper surface, and a concave plane that is more concave than the upper surface. A concave surface located on the concave plane, a flat surface that forms a common surface with the upper surface, a convex surface that is more convex than the upper surface, and a concave portion that is positioned on the convex plane, the depth of which is from the upper surface Or a concave portion larger than the height of the convex state of the convex plane , or a flat surface that forms a common surface with the upper surface,
The inclined portion occupies a part of the height direction of the side surface of the convex structure portion, and the start portion of the inclined portion coincides with the flat surface that forms a common surface with the upper surface of the convex structure portion, and excludes the inclined portion. The side surface of a convex structure part is perpendicular | vertical with respect to the upper surface of the said convex structure part, The mold for nanoimprint characterized by the above-mentioned.   2. The nanoimprint mold according to claim 1, wherein the inclined portion has a concave shape recessed in an inner direction of the convex structure portion.   The nanoimprint mold according to claim 1 or 2, wherein an angle formed by the inclined portion and the upper surface of the convex structure portion is within a range of 10 ° to 60 °.   The said transfer shape part has a recessed part, The height requested | required from the upper surface of the said convex structure part to the completion | finish site | part of an inclined part is larger than the maximum depth of the said recessed part, The Claim 1 thru | or 3 characterized by the above-mentioned. The mold for nanoimprints according to any one of the above.   5. The mold for nanoimprint according to claim 4, wherein in the height direction of the convex structure portion, the end portion of the inclined portion and the deepest portion of the concave portion are spaced apart by 10 μm or more. A photocurable resin droplet is supplied to a substrate, and the nanoimprint mold according to any one of claims 1 to 5 is brought into contact with the droplet to form a photocurable resin layer. And curing the photocurable resin layer, and then releasing the cured resin layer and the mold,
When the photocurable resin layer is formed by bringing the transfer forming portion of the nanoimprint mold into contact with the droplets, the photocurable resin layer is in contact with the inclined portion of the convex structure portion, and the inclined A pattern forming method characterized by controlling so as not to contact a side surface of the convex structure portion excluding the portion.   While the inclined portion of the convex structure portion is in contact with the photocurable resin layer, and the side surface of the convex structure portion excluding the inclined portion is adjusted so as not to contact the photocurable resin layer, the photocurable resin layer is adjusted. The pattern forming method according to claim 6, wherein the convex structure portion of the mold is pushed into the resin layer.

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