JP6729102B2 - Imprint mold manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing an imprint mold used in an imprint method.

In recent years, as a fine pattern forming technique replacing the photolithography technique, a pattern forming technique by an imprint lithography method using an imprint method has attracted attention. In the imprint method, for example, droplets of a photosensitive resist are supplied to a substrate provided with a chromium thin film, and a mold (mold member) having an uneven structure is brought into contact with the droplets of the photosensitive resist, so that the mold and the substrate are exposed. A photosensitive resist is spread between the materials. Then, in this state, the photosensitive resist is irradiated with light from the mold side to be cured to form a resist layer, and then the mold is released from the resist layer. As a result, a resist layer having an uneven structure in which the unevenness of the mold is reversed can be formed on the surface of the base material. After that, the residual film is removed from the resist layer to form a resist pattern, the chromium thin film is etched through this resist pattern to form a hard mask, and the base material is etched through this hard mask to form a pattern. Is done.
However, at the time of contact with the mold, the photosensitive resist protruding to the outside of the predetermined region is cured by the irradiated light at the same time as the photosensitive resist in the portion where the concavo-convex structure is to be formed to form a resist layer. When the mold is released from such a resist layer, there is a problem that a larger force acts than when the photosensitive resist does not protrude, and the mold and the resist layer (workpiece) having an uneven structure are damaged. is there.

In order to prevent the photosensitive resist from protruding to the outside of such a predetermined region, a lyophilic layer is formed in a predetermined region, a lyophobic layer is formed outside the lyophilic layer, and a lyophilic layer is formed on the lyophilic layer. A method of supplying droplets has been proposed (Patent Document 1).
On the other hand, by using a so-called mesa mold, which has an uneven structure on the upper plane of the convex structure protruding from the surroundings, the spread of the photosensitive resist to the outside of the site where the uneven structure is to be formed is limited. be able to. However, the photosensitive resist protruding from the convex structure portion of the mold adheres to the side wall surface of the convex structure portion and is cured at the same time as the photosensitive resist in the portion where the concave-convex structure is to be formed by the irradiation light. If the resist is present on the side wall surface of the convex structure portion of the mold as described above, then it may adhere to the mold as a foreign substance, which may adversely affect the imprint or damage the concave and convex structure of the mold.
Therefore, a film having water repellency or oil repellency is formed on the side wall surface of the convex structure portion of the mold to prevent the photosensitive resist protruding from the convex structure portion of the mold from adhering to the side wall surface of the convex structure portion. Has been proposed (Patent Document 2).

JP, 2008-100378, A JP, 2010-251601, A

However, Patent Document 2 does not disclose a specific method for forming a desired film on the side wall surface of the convex structure portion of the mold.
On the other hand, for example, a photosensitive material having water repellency or oil repellency is applied to a mold having a mesa structure by a spin coating method, the photosensitive material is subjected to pattern exposure, and then development is performed. It is conceivable to form a coating film having water repellency or oil repellency on the parts other than. However, in the spin coating method applied to a mold having a mesa structure, thickness unevenness occurs, and it is difficult to form a highly accurate pattern by pattern exposure, and the side wall surface of the convex structure portion of the mold, especially on the upper plane of the convex structure portion is formed. The formation of a film on the near side wall surface is likely to be hindered. In this way, when the formation of the coating film is hindered and the side wall surface near the upper plane of the convex structure portion is exposed, the above-described resist adhesion is likely to occur.

Such a problem is not limited to the formation of the above-mentioned water-repellent or oil-repellent coating,
This is the same problem that occurs when a side wall surface of a convex structure portion of a mold having a mesa structure is covered with a desired functional film, such as when forming a light shielding film.
The present invention has been made in view of the above situation, and is a method for manufacturing an imprint mold having a mesa structure, which is provided with a desired functional film on a sidewall surface of a convex structure portion. The purpose is to provide.

In order to achieve such an object, the present invention provides a base integrally having a base portion and a convex structure portion protruding from one surface of the base portion, and a concavo-convex structure pattern located on the upper plane of the convex structure portion. And a droplet of a curable resist on the upper surface of the convex structure portion of a base integrally having a base portion and a convex structure portion protruding from one surface of the base portion. And a step of bringing the flat surface of the processed substrate having a predetermined flat surface close to the upper plane of the convex structure section, and A contact step of developing the resist between them to form a resist layer, a curing step of curing the resist layer, a releasing step of separating the cured resist layer and the processed substrate, and a coating of the resist layer. As described above, a film forming step of forming a functional film on the base portion and the convex structure portion of the base, and removing the resist layer, and at the same time, removing the functional film covering the resist layer. In the contacting step, the resist that develops between the upper flat surface of the convex structure portion and the flat surface of the processed substrate is a peripheral edge of the upper flat surface of the convex structure portion, or near the peripheral edge. And the resist protruding from between the upper flat surface of the convex structure portion and the flat surface of the processed substrate is pushed up to the side wall surface located at the periphery of the flat surface of the processed substrate. did.
As another aspect of the present invention, the size of the planar surface shape of the flat surface of the processed substrate is equal to or smaller than the size of the planar surface shape of the upper plane of the convex structure portion.
As another aspect of the present invention, the difference in the peripheral portion when the planar view shape of the flat surface of the processed substrate and the planar view shape of the upper plane of the convex structure portion are overlapped is within a range of 1 to 5 μm. It has a certain structure.
As another aspect of the present invention, the contact angle between the resist protruding from the upper plane of the convex structure portion and the flat surface of the processed substrate and the side wall surface located on the periphery of the flat surface of the processed substrate is θ1. When the contact angle between the resist and the upper plane of the convex structure portion is θ2, the relationship of (θ1−θ2)≦37° is established.
As another aspect of the present invention, the processed substrate integrally has a base portion and a convex structure portion protruding from one surface of the base portion, and an upper plane of the convex structure portion is the flat surface. It was configured.
As another aspect of the present invention, it is configured to include a pattern forming step of forming a concavo-convex structure pattern on the upper plane of the convex structure portion of the substrate before the droplet supply step.
As another aspect of the present invention, after the removing step, there is provided a pattern forming step of forming an uneven structure pattern on the upper plane of the convex structure portion of the base.
As another aspect of the present invention, in the film forming step, any one of a water repellent film, a hydrophilic film, a light shielding film, and a conductive film is formed as a functional film.
As another aspect of the present invention, the processed substrate has a groove portion in the vicinity of the peripheral edge of the flat surface.

The method for producing an imprint mold of the present invention is a sidewall surface of a convex structure portion of a mold having a mesa structure, and a desired functional film is formed up to the end of the sidewall surface located on the upper plane side of the convex structure portion. It is possible to manufacture the provided imprint mold.

FIG. 1 is a plan view showing an example of an imprint mold manufactured by the method for manufacturing an imprint mold of the present invention. FIG. 2 is a vertical cross-sectional view taken along line II of the imprint mold shown in FIG. FIG. 3 is a partially enlarged sectional view of FIG. FIG. 4 is a process chart for explaining one embodiment of the method for manufacturing an imprint mold of the present invention. FIG. 5 is a process chart for explaining one embodiment of the method for manufacturing an imprint mold of the present invention. FIG. 6 is a plan view showing a state in which the processed substrate is brought close to the upper plane of the convex structure portion of the base. FIG. 7 is a diagram showing a state in which a resist is formed by developing a resist between the upper plane of the convex structure portion of the base and the flat surface of the processed substrate. FIG. 8 is a view showing the resist protruding from between the upper plane of the convex structure portion of the base and the flat surface of the processed substrate. FIG. 9 is a diagram showing a relationship between the contact angle difference (θ1−θ2) and d/hc showing the shape of the resist that protrudes. FIG. 10 is a cross-sectional view showing another example of the base of the imprint mold. FIG. 11 is a partial cross-sectional view showing another example of the processed substrate used for manufacturing the imprint mold. 12 is a plan view showing a flat surface of the processed substrate shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that the drawings are schematic or conceptual, and the dimensions of each member, the ratio of sizes between members, and the like are not necessarily the same as the actual ones, and the same members and the like may be represented. However, the dimensions and ratios may be different depending on the drawings.
First, an example of the imprint mold manufactured by the method for manufacturing an imprint mold of the present invention will be described. FIG. 1 is a plan view showing an example of an imprint mold manufactured by the method for manufacturing an imprint mold of the present invention, FIG. 2 is a vertical sectional view taken along line I-I of the imprint mold shown in FIG. 1, and FIG. 3 is a partially enlarged sectional view of FIG. 2.

In the embodiment shown in FIGS. 1 to 3, the imprint mold 11 includes a base 12 integrally having a base 13 and a convex structure 14 protruding from one surface 13 a of the base 13, and a base 12 having the convex structure 14. It has the concavo-convex structure pattern 15 located on the upper flat surface 14a, and the functional film 17 located so as to cover the side wall surface 14b of the convex structure portion 14 and the surface 13a of the base portion 13. The functional film 17 is omitted in FIGS. 1 and 2, and the concavo-convex structure pattern 15 is omitted in FIG.
As described above, the base 12 that constitutes the imprint mold 11 has a so-called mesa structure that integrally has the convex structure portion 14 that protrudes from the one surface 13 a of the base portion 13. The protrusion height H of the convex structure portion 14 can be appropriately set in the range of 3 μm to 3 mm, for example. In the illustrated example, the plan view shape of the upper plane 14a of the convex structure portion 14 is rectangular, but the shape is not limited to this, and may be a desired shape such as a circle, and the size of the upper plane 14a is set appropriately. can do.

The material of the substrate 12 can be appropriately determined according to the usage conditions of the imprint mold 11. For example, when the resin composition or the like that is the material to be transferred is photo-curable, a material that can transmit the irradiation light for curing these can be used, such as quartz glass, silicate glass, and calcium fluoride. In addition to glass materials such as magnesium fluoride and acrylic glass, sapphire and gallium nitride, resins such as polycarbonate, polystyrene, acryl and polypropylene, and any laminated materials thereof can be used. The imprint mold 11 has a light-transmitting property when the material to be transferred used is not photocurable or when light for curing the material to be transferred can be irradiated from the transfer substrate side. Since it is not necessary, the substrate 12 does not have to be a light-transmissive material, and in addition to the above materials, for example, metals such as silicon, nickel, titanium, and aluminum, and alloys, oxides, nitrides thereof, or Any of these laminated materials can be used.
The concavo-convex structure pattern 15 has a concave portion 15a formed on the upper flat surface 14a of the convex structure portion 14. The pattern shape, pattern size, pattern type, etc. of the concavo-convex structure pattern 15 can be appropriately set according to the purpose of use of the imprint mold 11.

The functional film 17 is located so as to cover the side wall surface 14b of the convex structure portion 14 and the surface 13a of the base portion 13. Therefore, the functional film 17 covers the upper end of the side wall surface 14b of the convex structure 14, that is, the end on the upper plane 14a side. Such a functional film 17 can be appropriately set, for example, a water repellent film, a hydrophilic film, a light shielding film, a conductive film, or the like, depending on the purpose of use of the imprint mold 11. Further, the thickness of the functional film 17 can be appropriately set so that the functional film 17 can express a desired function.
4 and 5 are process diagrams for explaining one embodiment of the method for manufacturing an imprint mold of the present invention, which is an example of manufacturing the imprint mold 11 shown in FIGS. 1 to 3. Although FIG. 4 and FIG. 5 show a cross section corresponding to FIG. 3, in the embodiment of this manufacturing method, the concavo-convex structure pattern 15 is formed on the upper flat surface 14a of the convex structure portion 14 by a removing step described later. The example is performed after. Therefore, in FIGS. 4 and 5, on the upper plane 14a of the convex structure portion 14, there is no concave portion 15a forming the concave-convex structure pattern 15.
In the method of manufacturing the imprint mold of the present invention, in the droplet supply step, the base 12 having the mesa structure integrally having the base 13 and the convex structure 14 protruding from the one surface 13a of the base 13 is Droplets of the curable resist 21 are supplied to the upper plane 14a of the convex structure portion 14 (FIG. 4A). The curable resist 21 used is not particularly limited, and a known photocurable resist or thermosetting resist can be used.

The amount of droplets of the supplied resist 21 is, for example, the volume of the gap when the processed substrate used in the subsequent process and the upper plane 14a of the convex structure portion 14 are brought close to each other, the amount of resist attached to the side wall surface of the processed substrate described later, and the like. Can be set in consideration.
Next, in the contacting step, using the processed substrate 32 having the predetermined flat surface 34a, the flat surface 34a is brought close to the upper plane 14a of the convex structure portion 14 of the base 12 and the upper plane 14a of the convex structure portion 14 is formed. The resist 21 is developed between the processed substrate 32 and the flat surface 34a to form a resist layer 22 (FIG. 4B). In this contact step, the resist 21 reaches the peripheral edge of the upper plane 14a of the convex structure portion 14 of the base 12 or near the peripheral edge, and forms the upper plane 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32. The resist 21 protruding from between the spaces rises to the side wall surface 34b located at the peripheral edge of the flat surface 34a of the processed substrate 34. Therefore, the end 22a of the formed resist layer 22 is located on the side wall surface 34b of the peripheral edge of the flat surface 34a of the processed substrate 32.
In the illustrated example, the processed substrate 32 has a mesa structure integrally including a base portion 33 and a convex structure portion 34 protruding from one surface 33 a of the base portion 33. The upper plane of the convex structure portion 34 is a flat surface 34a, and the side wall surface of the convex structure portion 34 is a peripheral side wall surface 34b of the flat surface 34a. In this case, the height H′ of the convex structure portion 34 of the processed substrate 32 is larger than the height of the end 22 a of the resist layer 22 located on the side wall surface 34 b located on the periphery of the flat surface 34 a of the processed substrate 34. To do.

The flat surface 34a of the processed substrate 32 has a resist 21 that develops between the upper plane 14a of the convex structure portion 14 of the base 12 and the flat surface 34a of the processed substrate 32. Alternatively, the resist 21 that reaches the vicinity of the peripheral edge and protrudes from between the upper flat surface 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32 is located on the peripheral edge of the flat surface 34a of the processed substrate 32. It has a plan view shape that makes it possible to approach FIG. 6 is a plan view showing a state in which the flat surface 34 a of the processed substrate 32 is brought close to the upper plane 14 a of the convex structure portion 14 of the base 12, and the peripheral portion of the upper plane 14 a of the convex structure portion 14 in a plan view shape. Is indicated by a solid line, and the peripheral edge of the flat surface 34a of the processed substrate 32 in a plan view is indicated by a chain line. In the example shown in FIG. 4B, the size of the flat surface 34a of the processed substrate 32 in plan view is smaller than the size of the upper plane 14a of the convex structure portion 14 in plan view. Therefore, as shown in FIG. 6, the processed substrate 32 is brought close to the base 12 so that the planar surface shape of the flat surface 34a of the processed substrate 32 falls within the planar surface shape of the upper plane 14a of the convex structure portion 14. When they are overlapped with each other, a dimensional difference D occurs due to a difference in shape size at the peripheral portion. This dimensional difference D is determined in consideration of the wettability between the flat surface 34a of the processed substrate 32, the side wall surface 34b and the resist 21 used, the wettability between the upper plane 14a of the convex structure portion 14 and the resist 21 used, and the like. As shown in FIG. 4B, it is set so that the end 22a of the resist layer 22 can be located on the side wall surface 34b at the periphery of the flat surface 34a of the processed substrate 32.

When the above-mentioned dimensional difference D is small, the surplus of the resist 21 protruding outside from the gap between the upper plane 14a of the convex structure 14 and the flat surface 34a of the processed substrate 32 adheres to the side wall surface 14b of the convex structure 14. It is not preferable because it may occur.
On the other hand, the size of the flat surface 34a of the processed substrate 32 determines the range in which the resist 21 develops toward the peripheral edge of the upper plane 14a of the convex structure portion 14. For example, as shown in FIG. 7, when the dimensional difference D is large, the end 22a of the resist layer 22 located on the side wall surface 34b at the periphery of the flat surface 34a of the processed substrate 32 has the upper surface 14a of the convex structure portion 14 at the end. It is in a state where it has not reached the periphery. In this state, the upper flat surface 14a of the convex structure portion 14 is exposed in a range near the periphery thereof, for example, in a range of a distance L from the periphery. The distance L determines the range in which the functional film formed as described below exists on the upper plane 14a of the convex structure portion 14. Therefore, the distance L can be set within a range that does not impair the function of the functional film required for the imprint mold to be manufactured, the imprint suitability, and the like. Therefore, the upper limit of the dimension difference D can be set in consideration of the allowable range of the distance L, the wettability between the sidewall surface 34b of the processed substrate 32 and the resist 21 used, and the like.

The dimensional difference D of the peripheral portion when the planar shape of the flat surface 34a of the processed substrate 32 described above is overlapped so as to fit inside the planar shape of the upper flat surface 14a of the convex structure portion 14 is, for example, 0 to It can be in the range of 10 μm, preferably 1 to 5 μm. Incidentally, in the example shown in FIG. 7, the planar shapes of the square upper plane 14a and the flat surface 34a are overlapped so that the centers of gravity of the squares coincide with each other, and the dimensional difference D in the four side directions becomes equal. There is. However, due to the accuracy limit of mechanical control when the flat surface 34a of the processed substrate 32 is brought close to the upper plane 14a of the convex structure portion 14 of the base 12, a slight difference may occur in the dimensional difference D in the four side directions. .. Therefore, in setting the dimensional difference D of the peripheral portion described above, it is preferable to consider the accuracy limit of such mechanical control.

Here, as shown in FIG. 8, with respect to the resist 21 protruding from between the upper plane 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32, the sidewall surface located at the periphery of the flat surface 34a of the processed substrate 34. The height from the upper plane 14a of the end portion 22a of the resist layer 22 formed so as to rise to 34b is set to hc, and the end portion 22b of the resist layer 22 located on the upper plane 14a of the convex structure portion 14 is processed by the processed substrate 32. The distance from the end of the flat surface 34a is d. Then, the height hc and the distance d are obtained by simulation from the contact angle θ1 of the resist 21 on the side wall surface 34b of the processed substrate 32 and the contact angle θ2 of the resist 21 on the upper flat surface 14a of the convex structure 14 as follows. The results are shown in Tables 1 to 3. For the simulation, refer to PHYSICS OF FLUIDS 17, 122104 (2005), in which the distance between the upper plane 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32, that is, the thickness t of the resist layer 22 is defined as follows. A state in which the liquid level of the resist that has leached out is set to 15 nm is 15 nm above the upper plane 14a of the convex structure 14 and is located at a location P 30 nm away from the end of the flat surface 34a of the processed substrate 32 is calculated. did. Even when the liquid level of the resist that has leached out is greater than 30 nm from the end of the flat surface 34a of the processed substrate 32, the upper surface 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32 are not separated. The resist 21 protruding from the space oozes out while maintaining the contact angles θ1 and θ2 as shown by the chain double-dashed line in FIG. 8, but the details are omitted.
In Table 1, Table 2 and Table 3, the contact angle θ2 is fixed at θ2=20° (Table 1), θ2=30° (Table 2) and θ2=40° (Table 3), respectively, and the contact angle θ1 is The height hc, the distance d, and the d/hc at θ1 and θ2 are set by setting the pitch at 10° between 10° and 70°.

As shown in Tables 1 to 3, when the contact angle θ2 is fixed, the change width of hc is small, and the larger the contact angle θ1, the larger the distance d.
In addition, as shown in FIG. 8, the distance between the upper flat surface 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32, that is, the thickness t of the resist layer 22 is fixed at 15 nm, 30 nm, 60 nm, and 90 nm, respectively. Similarly, the height hc and the distance d when the contact angle is θ1=θ2=20° are obtained by the same simulation, and the results are shown in Table 4 below.

表４に示されるように、レジスト層２２が厚くなっても、凸構造部１４の上平面１４ａと加工基板３２の平坦面３４ａとの間からのレジスト２１のはみ出しは、ｄ／ｈｃの比を維持したものとなる。

As shown in Table 4, even if the resist layer 22 becomes thicker, the protrusion of the resist 21 from between the upper flat surface 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32 has a d/hc ratio. It will be maintained.

FIG. 9 is a diagram showing a relationship between the contact angle difference (θ1−θ2) and d/hc showing the shape of the resist 21 protruding from the results obtained by simulation as shown in Tables 1 to 4 above. is there. As shown in FIG. 9, d/hc is determined by the contact angles θ1 and θ2. For example, the contact angle θ2 of the resist 21 on the upper plane 14a of the convex structure 14 is determined from the material used. In this case, by setting the contact angle θ1 of the resist 21 on the side wall surface 34b of the processed substrate 32, the shape of the resist 21 (d/hc) protruding from between the upper plane 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32 is set. ) Can be controlled. The shape (d/hc) of the resist 21 can be controlled so that the distance d is equal to or less than the above-mentioned dimensional difference D, and for example, (θ1−θ2)≦37° between the contact angles θ1 and θ2. That is, the control becomes easy under the condition that the relationship of 0≦d/hc≦2 is established.
As the material of the above-mentioned processed substrate 32, when the resist 21 is photocurable and the light is irradiated from the processed substrate 32 side, a material that can transmit the irradiation light can be used, such as quartz glass or silicate glass. In addition to glass materials such as calcium fluoride, magnesium fluoride, and acrylic glass, sapphire and gallium nitride, resins such as polycarbonate, polystyrene, acryl, and polypropylene, or any laminated material thereof can be used. Further, when the resist 21 is not photo-curable or when light for curing the resist 21 can be irradiated from the side of the base 12, the processed substrate 32 does not need to be light-transmissive. In addition to the above materials, for example, metals such as silicon, nickel, titanium, and aluminum, their alloys, oxides, nitrides, or any laminated materials thereof can be used.

Next, in the curing step, the resist layer 22 is cured, and then, in the releasing step, the cured resist layer 23 and the processed substrate 32 are separated from each other to position the resist layer 23 on the convex structure portion 14 of the base 12. The state is set (FIG. 5(A)).
Next, in the film forming step, the functional film 17 is formed on the surface 13a of the base 13 and the convex structure 14 of the base 12 so as to cover the resist layer 23 (FIG. 5B). As described above, the functional film 17 can be formed according to the intended use of the imprint mold to be manufactured. For example, a water-repellent film, a hydrophilic film, a light-shielding film, a conductive film, or the like can be used as the functional film. Can be formed as. Such a functional film 17 is, for example, a known wet film forming method such as a spray method, a dip coating method, a spin coating method, a sputtering method, a vacuum evaporation method, in consideration of a film forming material to be used, a thickness, and the like. It can be formed by a known dry film forming method such as a chemical vapor deposition method or an ion plating method. When the functional film 17 is a water-repellent film, for example, a thin film of a fluorine-based silane coupling agent can be formed by a dip coating method, a spin coating method, or a chemical vapor deposition method.

Next, in a removing step, the resist layer 23 is removed, and at the same time, the functional film 17 covering the resist layer 23 is removed (FIG. 5C). As a result, the base 12 is provided with the functional film 17 on the side wall surface 14b of the convex structure 14 up to the end of the convex structure 14 on the upper plane 14a side.
In the embodiment of the method for manufacturing the imprint mold described above, the imprint mold can be obtained by forming the concavo-convex structure pattern 15 on the upper plane 14a of the convex structure 14 after the removing step. Further, in the method for manufacturing the imprint mold of the present invention, the concavo-convex structure pattern 15 may be formed on the upper flat surface 14a of the convex structure portion 14 before the above-mentioned droplet supply step.

Here, the concavo-convex structure pattern 15 can be formed on the upper plane 14a of the convex structure portion 14 by using the concavo-convex structure pattern forming method in the known imprint mold manufacturing method. For example, a hard mask material layer of chromium or the like is formed on the upper plane 14a of the convex structure portion 14, and a resist pattern is formed on the hard mask material layer by photolithography, imprint lithography, electron beam lithography, or the like. Then, the hard mask material layer is etched through the resist pattern to form a hard mask, and then the convex structure portion 14 is etched through the hard mask, and the remaining hard mask is removed to form the concave-convex structure pattern. The formation of 15 is completed.
Such an imprint mold manufacturing method of the present invention is an imprint in which a desired functional film is provided on a sidewall surface of a convex structure portion of a mold having a mesa structure up to an end portion on the upper plane side of the convex structure portion. It becomes possible to manufacture a mold.
The above-described embodiment is an exemplification, and the method for manufacturing an imprint mold of the present invention is not limited to such an embodiment. For example, as shown in FIG. 10, the base 12 used in the imprint mold may have a concave structure portion 18 on the surface 13b of the base 13 opposite to the surface 13a on which the convex structure portion 14 is located. Good. The plan view shape of the opening of the concave structure portion 18 is a size including the plan view shape of the convex structure portion 14. Further, the shape of the opening of the concave structure portion 18 is preferably circular in plan view, but the shape is not limited to this and may be a desired shape.
Further, the processed substrate 32 may have a concave structure portion on the surface opposite to the surface 33a of the base portion 33 on which the convex structure portion 34 is located.

Furthermore, the entire flat surface 34a of the processed substrate 32 may be flat, or may have a groove or the like at a desired position. In general, the development of the droplets of the resist 21 between the upper flat surface 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32 proceeds around the portion where the droplet is supplied to the upper flat surface 14a of the convex structure portion 14. To do. Therefore, the front end of the resist 21 toward the peripheral edge of the flat surface 34a of the processed substrate 32 has a shape in which arcs centering on a plurality of droplet supply sites are continuous. For this reason, there is a time lag in reaching the periphery of the flat surface 34a, which may cause variations in the amount of the resist 21 protruding from between the upper flat surface 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32. Therefore, the flat surface 34a of the processed substrate 32 is provided with a groove portion and a concave portion for making the development of the resist 21 uniform between the upper plane 14a of the convex structure portion 14 and the flat surface 34a of the processed substrate 32. Good. For example, the flat surface 34a may have grooves radially from the center toward the periphery. Further, the flat surface 34a may have a fine groove portion 35 near the peripheral edge along the peripheral edge of the flat surface 34a. FIG. 11 is a partial cross-sectional view showing such a processed substrate, and FIG. 12 is a plan view showing a flat surface of the processed substrate. In the processed substrate 32 as shown in FIGS. 11 and 12, the groove portion 35 is located along the peripheral edge of the flat surface 34a, so that the resist 21 that has reached the groove portion 35 first has a capillary force in the fine groove portion 35. Thus, the resist 21 that moves along the peripheral edge of the flat surface 34a and reaches the groove 35 later is joined. Then, after the groove portion 35 is filled with the resist 21, the resist 21 develops toward the peripheral edge of the flat surface 34a, so that it is possible to suppress the occurrence of a time difference when the resist 21 reaches the peripheral edge of the flat surface 34a. Therefore, the amount of the resist 21 protruding from between the upper flat surface 14 a of the convex structure portion 14 and the flat surface 34 a of the processed substrate 32 can be made uniform at the peripheral edge of the flat surface 34 a of the processed substrate 32.

[Example 1]
A base (material: quartz glass) integrally having a base (152 mm×152 mm, thickness 6.35 mm) and a convex structure (30 mm square, height 30 μm) protruding from the center of one surface of the base was prepared. ..
Further, a processed substrate (material: quartz glass) integrally having a base (152 mm×152 mm, thickness 6.35 mm) and a convex structure (30 mm square, height 30 μm) protruding from the center of one surface of the base. Prepared. The upper plane of the convex structure portion of this processed substrate is a flat surface, and when this flat surface and the upper plane of the convex structure portion of the above-mentioned substrate are superposed, the size of the plan view shape of the flat surface of the processed substrate is The size difference D (see FIG. 6), which is smaller than the size of the plan view shape of the upper plane of the convex structure portion of the base body and is generated in the peripheral portion, was 2 μm.
Droplets of a photocurable resist were supplied onto the convex structure portion of the substrate by an inkjet method.

Next, the flat surface, which is the upper plane of the convex structure section of the processed substrate, is brought close to the upper plane of the convex structure section of the base body to which the resist is supplied, and the upper plane of the convex structure section of the base body and the processed substrate. A resist layer was formed by spreading the resist between the flat surface and the flat surface. When the periphery of the convex structure portion of the processed substrate in this state was observed, the resist layer protruded from between the upper plane of the convex structure portion of the substrate and the flat surface of the processed substrate. The resist layer reaches the peripheral edge of the upper plane of the convex structure of the substrate, the contact angle θ2 with the upper plane is about 20°, and the end portion of the resist layer is the peripheral edge of the flat surface of the processed substrate. And the contact angle θ1 with the side wall surface was about 20°. Further, as a result of measuring the height hc of the resist layer and the distance d (see FIG. 8), d/hc≈1.
Then, parallel light (ultraviolet light having a peak wavelength of 365 nm) was applied to the processed substrate side under the condition of 1000 mJ/cm ² . Thereby, the resist layer was cured. Then, the cured resist layer and the processed substrate were separated from each other, and the resist layer was placed on the convex structure portion of the substrate.
Next, a fluorine-based silane coupling agent (Durasurf manufactured by Harves Co., Ltd.) was applied to the substrate on which the resist layer was formed as described above by a spin coating method and dried. As a result, a water repellent film was formed as the functional film. This water-repellent film covers not only the resist layer but also the base of the base and the side wall of the convex structure.

Then, the resist layer was removed using a resist stripper. Simultaneously with the removal of the resist layer, the water-repellent film covering the resist layer was removed, but the water-repellent film covering the side walls of the base and the convex structure of the substrate remained.
As a result of observing the base surface and the side wall surface of the convex structure portion of the substrate on which the water-repellent film is formed by energy dispersive X-ray spectrometry (EDX), the side wall surface of the convex structure portion of the base body is observed. In addition, it was confirmed that the water-repellent film was present up to the upper planar end of the convex structure.
Next, a chromium thin film was formed as a hard mask material layer on the upper plane of the convex structure portion of the substrate by a sputtering method, and a resist pattern was formed on the chromium thin film by an imprint lithography method. Then, the chromium thin film was etched through the resist pattern to form a hard mask, and then the convex structure portion was etched through this hard mask to remove the remaining hard mask. As a result, an imprint mold provided with the concavo-convex structure pattern on the upper plane of the convex structure portion was obtained.
As a result of observing the base portion of the base body and the side wall surface of the convex structure portion constituting the imprint mold in the same manner as above, the side wall surface of the convex structure portion of the imprint mold is extended to the end of the convex structure portion on the upper plane side. It was confirmed that a water repellent layer was present.

[Example 2]
A water-repellent film was formed in the same manner as in Example 1 except that a substrate having a concavo-convex structure pattern formed in advance on the upper plane of the convex structure portion was used to obtain an imprint mold.
As a result of observing the base and the side wall surface of the convex structure of the imprint mold in the same manner as in Example 1, the side wall of the convex structure of the imprint mold has an end on the upper plane side of the convex structure. It was confirmed that the water repellent layer was present.

[Comparative example]
A substrate similar to that of Example 1 was prepared, and a photocurable resist was supplied to the convex structure portion of the substrate to apply it by the spin coating method, and then dried. As a result, a resist layer was formed on the upper plane of the convex structure portion of the base, the side wall surface and the base of the base. Then, this resist layer was pattern-exposed and developed to make the resist layer positioned on the convex structure portion of the substrate.
Then, in the same manner as in Example 1, a water-repellent film was formed on the substrate on which the resist layer was formed, and thereafter, the resist layer was removed and, at the same time, the water-repellent film covering the resist layer was removed.
As a result of observing the base portion of the substrate on which the water-repellent film is formed and the side wall surface of the convex structure portion in the same manner as in Example 1, as a result of the observation of the side wall surface of the convex structure portion of the substrate on the upper plane side, the end portion of the upper plane surface From this, it was confirmed that there is a site where the substrate is exposed without being covered with the water-repellent film in a width of about 1 μm.

It is useful for manufacturing an imprint mold having a so-called mesa structure.

DESCRIPTION OF SYMBOLS 11... Imprint mold 12... Base|substrate 13... Base part 14... Convex structure part 14a... Upper plane of convex structure part 14b... Side wall surface of convex structure part 15... Uneven structure pattern 17... Functional film 18... Concave structure part 32... Processing Substrate 34... Convex structure portion 34a... Flat surface of convex structure portion 34b... Side wall surface of convex structure portion

Claims (9)

In a method for manufacturing an imprinting mold, including a base integrally having a base and a convex structure protruding from one surface of the base, and a concavo-convex structure pattern located on an upper plane of the convex,
A droplet supply step of supplying a curable resist droplet to the upper plane of the convex structure portion of a base integrally having a base portion and a convex structure portion protruding from one surface of the base portion;
The flat surface of the processed substrate having a predetermined flat surface is brought close to the upper plane of the convex structure portion, and the resist is developed by developing the resist between the upper plane of the convex structure portion and the flat surface of the processed substrate. A contacting step to form a layer,
A curing step of curing the resist layer,
A mold release step of separating the cured resist layer and the processed substrate,
A film forming step of forming a functional film on the base portion and the convex structure portion of the substrate so as to cover the resist layer;
A removing step of removing the resist layer and at the same time removing the functional film covering the resist layer,
In the contact step, the resist that develops between the upper plane of the convex structure and the flat surface of the processed substrate is made to reach the periphery of the upper plane of the convex structure, or near the periphery, and A method of manufacturing an imprint mold, characterized in that the resist protruding from between the upper plane of the convex structure portion and the flat surface of the processed substrate is pushed up to the side wall surface located at the periphery of the flat surface of the processed substrate. .. The method of manufacturing an imprint mold according to claim 1, wherein the size of the planar surface shape of the flat surface of the processed substrate is equal to or smaller than the size of the planar surface shape of the upper plane of the convex structure portion. The difference between the peripheral portions when the planar view shape of the flat surface of the processed substrate and the planar view shape of the upper plane of the convex structure portion are overlapped is within a range of 1 to 5 μm. 2. The method for manufacturing the imprint mold according to 2. The contact angle between the resist protruding from the upper plane of the convex structure portion and the flat surface of the processed substrate and the side wall surface located at the periphery of the flat surface of the processed substrate is θ1, the resist, and the convex structure portion. The production of the imprint mold according to any one of claims 1 to 3, wherein a relation of (θ1-θ2) ≤ 37° is established, where θ2 is a contact angle with the upper plane. Method. The processed substrate integrally includes a base portion and a convex structure portion protruding from one surface of the base portion, and an upper plane of the convex structure portion is the flat surface. Item 5. A method for manufacturing an imprint mold according to any one of Items 4. 6. The imprint according to claim 1, further comprising a pattern forming step of forming a concave-convex structure pattern on an upper plane of the convex structure portion of the substrate before the droplet supplying step. Mold manufacturing method. The manufacturing of the imprint mold according to claim 1, further comprising a pattern forming step of forming an uneven structure pattern on an upper plane of the convex structure portion of the base after the removing step. Method. 8. The imprint according to claim 1, wherein in the film forming step, any one of a water repellent film, a hydrophilic film, a light shielding film, and a conductive film is formed as a functional film. Mold manufacturing method. The method for manufacturing an imprint mold according to claim 1, wherein the processed substrate has a groove portion near a periphery of the flat surface.

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