JP2015167203A - Pattern forming method and patterned substrate manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable formation of an irregular pattern at low cost and with high yield while suppressing occurrence of defects.SOLUTION: A nanoimprint mold 1 to be used has, on the surface thereof, a main pattern area in which an irregular pattern to be transferred is formed, and a non-main pattern area 3 which is adjacent to the main pattern area 2 and is a dummy pattern having a pattern density or aspect ratio smaller than the irregular pattern or a flat face. Plural kinds of resist liquid 12, 13 which have different components and are different in release force after cured are prepared as resist liquid. In a coating step, resist liquid 12 which is relatively low in the release force after cured is disposed in the area corresponding to the main pattern area 2 on the surface of the nanoimprint substrate 10. A resist liquid 13 which is relatively high in release force after cured is disposed at at least a part of the area 3 corresponding to the non-main pattern area.

Description

  The present invention relates to a pattern forming method by an imprint method and a patterned substrate manufacturing method.

  The imprint method is a pattern that corresponds to the pattern on the mold by pressing a mold (mold) whose pattern has been processed in a concavo-convex shape in advance onto the resist layer applied on the substrate to be processed (processed substrate). In a field where miniaturization is required, such as a patterned media medium in a semiconductor element or a hard disk, it is attracting attention from the viewpoint of fine pattern formability, mass productivity, and cost. .

  As the resist, a thermoplastic or photo-curable one is used. Among these, a photo-imprint method using a photo-curable resist is expected as a next-generation manufacturing technology for fine processing. Has proposed a method using a plurality of resist materials having different etching rates in order to reduce CDU (non-uniform dimension) and make it uniform in a plane.

  In particular, in the nanoimprint method in nano-level pattern transfer, it is required to transfer a fine pattern with high accuracy and without generation of defects.

  In nanoimprints used in semiconductor lithography, it is extremely important to suppress the defects at the time of releasing the mold from the cured resist to improve the manufacturing process yield. In the nanoimprint method, it is empirically known that defects such as mogging and peeling occur frequently in the mold release process when the mold is peeled from the resist.

  Attempts have been made to devise a hardware surface (mold, substrate) involved in transfer of a mold, a substrate, or the like, or a device side such as a light source as a technique for suppressing defects that occur during mold release (Patent Documents 2 to 4). .

  Patent Document 2 discloses a method for suppressing the occurrence of defects in a main pattern by forming a dummy pattern having a high mold release force on a mold and using a dummy pattern region as a mold termination end in a nanoimprint method. .

  Patent Document 3 discloses that a method of controlling a release force by adjusting an exposure amount (dose) by utilizing the fact that the degree of cure of a photocurable resin depends on an exposure amount, and a release end portion that tends to increase the release force. A method for reducing the exposure amount is disclosed. Further, Patent Document 4 proposes reducing the mold release force of the pattern transfer region by sharpening the shape of the four corners of the mesa structure.

  Further, in Patent Document 5, two types of curable resin materials having different release forces are used as resists, and the resist is partially applied in the transfer pattern, so that the impact on the mold and the resist layer at the time of release is disclosed. A method of reducing defects and suppressing the occurrence of defects is disclosed.

JP 2011-61195 A JP 2011-116032 A JP 2012-212781 A JP 2011-116032 A JP 2012-114158 A

  However, in the method described in Patent Document 2, the pattern density of the dummy pattern is set higher than that of the main pattern to increase the release force of the dummy pattern, and the occurrence of defects in the main pattern can be suppressed. It becomes easy to cause mold release defects such as mogging and peeling in the dummy pattern, and causes transfer defects due to dust being sandwiched between the substrate and the mold. In addition, a mold cleaning process or the like for preventing transfer failure is required, and the yield is reduced.

  In order to adjust the exposure amount described in Patent Document 3, a special optical system or system is required. In the method described in Patent Document 4, it is necessary to form a special mesa shape. Cost increases.

  As described in Patent Document 5, even if the timing of mold release is shifted depending on the site in the pattern to be transferred, mogging and peeling at the final end of the mold release cannot be sufficiently suppressed. In particular, when a part of the pattern to be transferred is the final end of the mold release, it becomes impossible to reuse the mold, leading to problems of high cost and low yield.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for suppressing the occurrence of defects, forming a pattern at a low cost and with a high yield, and a method for manufacturing a patterned substrate using the method. And

The uneven pattern forming method of the present invention includes a coating process in which a photo-curable resist solution is disposed at a desired position on a nanoimprint substrate, and a resist having a fine uneven pattern on the surface is applied to the nanoimprint substrate resist solution. A concavo-convex pattern forming method comprising: a pressing step that presses against the surface; a curing step that cures the resist solution to form a resist film; and a release step that releases the mold from the resist film,
As a mold, the main pattern area on which the uneven pattern to be transferred is formed and the non-main pattern area adjacent to the main pattern area and having a pattern density or aspect ratio smaller than the uneven pattern or a non-main pattern area that is a flat surface Use what you prepared for,
As resist solutions, prepare multiple resist solutions with different components and different release forces after curing,
In the coating process, a resist solution with a relatively low release force after curing is placed in the area corresponding to the main pattern area on the surface of the nanoimprint substrate, and corresponds to the non-main pattern area on the surface of the nanoimprint substrate. This is a concavo-convex pattern forming method in which a resist solution having a relatively high release force after curing is disposed in at least a part of a region to be cured.

  As the resist solution having a relatively high release force, a composition having an elastic modulus after curing larger than that after curing of the resist solution having a relatively low release force can be used.

  As a method for making the elastic modulus after curing larger than the elastic modulus after curing of a resist solution having a relatively low releasing force, photopolymerization contained in a resist solution having a relatively high releasing force A method in which the sensitivity of the initiator is higher than the sensitivity of the photopolymerization initiator contained in the resist solution having a relatively low release force, or many in the resist solution having a relatively high release force. A method is preferred in which the content of the functional polymerizable compound is larger than the content of the polyfunctional polymerizable compound in the resist solution having a relatively low release force.

  As a resist solution having a relatively high release force, the free energy per unit area at the interface with the mold after curing is a unit area at the interface with the mold after curing the resist solution with a relatively low release force. A composition that is smaller than the hit free energy can be used.

  As a method in which the free energy per unit area at the interface with the mold after curing is smaller than the free energy per unit area at the interface with the mold after curing of the resist solution having a relatively low release force As a resist solution having a relatively high releasing force, at least one photocurable resin component having at least one of an amine structure, a phosphate ester structure, a sulfate ester structure, and a polyalkylene oxide structure is used. As a resist solution having a relatively low release force using a composition containing two or more, the content of the photocurable resin component having a structure has the structure in the resist solution having a relatively high release force. As a method of using a composition smaller than the content of the photocurable resin component, or as a resist solution having a relatively high release force, the release agent content is How type force is small is used composition than the release agent content in the relatively low resist solution it is preferable.

  In the method for forming a concavo-convex pattern according to the present invention, a plurality of resist solutions are prepared by changing one or more components in stages, and a plurality of resist solutions are applied to the main pattern on the surface of the nanoimprint substrate in the coating process. You may arrange | position so that a component may change in steps from the area | region corresponding to an area | region to at least one part of the area | region corresponding to a non-main pattern area | region.

The method for producing a patterned substrate of the present invention forms a resist film having a concavo-convex pattern transferred on the surface of a nanoimprint substrate that is a substrate to be processed by the concavo-convex pattern forming method of the present invention,
This is a method for manufacturing a patterned substrate in which a substrate to be processed is etched using a resist film as a mask, and a concavo-convex pattern corresponding to the concavo-convex pattern transferred to the resist film is formed on the substrate to be processed.

According to the concavo-convex pattern forming method of the present invention, in the step of applying the resist solution to the nanoimprint substrate, the release force after curing is relatively low in the region corresponding to the main pattern region on the surface of the nanoimprint substrate. A resist solution is placed, and a resist solution having a relatively high release force after curing is placed on at least a part of the surface of the nanoimprint substrate corresponding to the non-main pattern region. The final end of the mold can be a non-main pattern region, and as a mold, a main pattern region on which a concavo-convex pattern to be transferred is formed, and a pattern density or aspect ratio that is adjacent to the main pattern region and is smaller than the concavo-convex pattern Non-main pattern that will be the final edge of mold release because it uses a dummy pattern or a non-main pattern area that is a flat surface on the surface Frequency can be suppressed because a small concave-convex pattern or a flat region, pattern density or aspect ratio, Moge upon release, the occurrence of defects such as peeling.
Since the generation of defects at the time of mold release can be suppressed, the yield is improved and the cost can be reduced.

Plane schematic diagram of a mold used in the uneven pattern forming method of the embodiment of the present invention It is the II-II sectional view taken on the line of the mold shown in FIG. It is a schematic diagram which shows the example of an uneven | corrugated pattern. It is a schematic cross section for demonstrating the aspect-ratio of an uneven | corrugated pattern. It is a perspective view for demonstrating the definition of the pattern density of an uneven | corrugated pattern. It is a perspective view for demonstrating the magnitude of a density pattern. It is a top view which shows typically the example of the arrangement pattern of the resist droplet on the nanoimprint board | substrate. It is a schematic diagram which shows the process of the uneven | corrugated pattern formation method of 1st Embodiment. It is a plane schematic diagram of the mold used with the uneven | corrugated pattern formation method of 2nd Embodiment. It is a schematic diagram which shows the process of the uneven | corrugated pattern formation method of 2nd Embodiment. It is a top view which shows typically the example of the arrangement pattern of the resist droplet on the board | substrate for nanoimprint of the uneven | corrugated pattern formation method of 3rd Embodiment. It is a schematic diagram which shows the process of the uneven | corrugated pattern formation method of 3rd Embodiment. It is a plane schematic diagram of the mold used by the 4th Embodiment uneven | corrugated pattern formation method. It is a top view which shows typically the example of the arrangement pattern of the resist droplet on the board | substrate for nanoimprint of the uneven | corrugated pattern formation method of 4th Embodiment. It is a schematic diagram which shows the process of the uneven | corrugated pattern formation method of 4th Embodiment. It is a plane schematic diagram of the mold used by the 5th Embodiment uneven | corrugated pattern formation method. It is a top view which shows typically the example of the arrangement pattern of the resist droplet on the board | substrate for nanoimprints of the uneven | corrugated pattern formation method of 5th Embodiment. It is a schematic diagram which shows the process of the uneven | corrugated pattern formation method of 5th Embodiment. It is a plane schematic diagram of the mold used in the Example and the comparative example. It is a plane schematic diagram of the mold used in the comparative example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, for easy visual recognition, the scale of each component in the drawings is appropriately changed from the actual one.

(Mold for nanoimprint)
First, the nanoimprint mold 1 used in the imprint method of the present embodiment will be described. FIG. 1 is a schematic view showing a plan view of the mold 1, and FIG. 2 is a cross-sectional view taken along the line II-II of the mold 1 shown in FIG.
As shown in FIGS. 1 and 2, the mold 1 includes a main pattern region 2 to be transferred to the surface and other non-main pattern regions 3. Here, the main pattern region 2 is a region where a concavo-convex pattern to be transferred to the substrate to be processed (hereinafter may be referred to as “main pattern”) is formed. The non-main pattern region 3 is a region other than the main pattern region 2 and is a flat region having no uneven pattern in this example. In the non-main pattern region 3, for example, a dummy pattern for adjusting the remaining resist film may be formed in nanoimprint lithography described later. The dummy pattern formation region in the non-main pattern region 3 is not particularly limited, and may be a part, a plurality of locations, or the entire main pattern region.

  In the mold 1 of the present invention, the dummy pattern is a concavo-convex pattern that is easier to release than the concavo-convex pattern (main pattern) to be transferred in the main pattern region 2. That is, the dummy pattern is a concavo-convex pattern having a smaller pattern density or aspect ratio than the main pattern formed in the main pattern region 2. Here, the concavo-convex pattern having a pattern density or aspect ratio smaller than that of the main pattern is at least 1) the pattern density is the same as the main pattern and the aspect ratio is small, and 2) the aspect ratio is the same as the main pattern and the pattern density is 3) In some cases, both the aspect ratio and the pattern density are smaller than the main pattern.

  When the dummy pattern is harder to release than the main pattern (for example, Patent Document 2 described above), that is, when the pattern density and pattern aspect ratio of the dummy pattern are larger than the main pattern, the mold is peeled off (released). When the mold is formed, the dummy pattern is less likely to be peeled off. Therefore, the mold release end where defects are likely to occur becomes a dummy pattern. As a result, the main pattern is protected from defects, but the dummy pattern at the end of mold release also has defects, and the resin defects adhere to the mold side, so that continuous imprinting cannot be performed. This is because if imprinting is performed with the defective resin attached, the force to peel off the dummy pattern that should originally be the mold release end is weakened. As a result, the main pattern is not the dummy pattern but the main pattern is released. This is because it ends. In order to avoid this, it is necessary to remove the resin dust adhering to the mold release defect by the cleaning imprint or the cleaning process every imprint, and each cleaning imprint or cleaning process is performed by imprint lithography. Cause a significant decrease in throughput.

The uneven pattern may be any pattern such as a line shape, a dot shape, or a combination thereof. FIG. 3A is a plan view showing an example of the concavo-convex pattern, and the hatched portion shows the planar shape of the convex portion 4.
As shown in FIG. 3B, the aspect ratio is a ratio H / W of the width W to the height (depth of the recess) H of the projection 4. As shown in FIGS. 3A (a) to 3A (c), when the planar shape of the convex portion 4 is elliptical or line-shaped, the width of the convex portion 4 is the length in the short side direction. When the convex part 10 as shown to 3A (d) is circular dot shape, let the width of the convex part 4 be the diameter. In the case of the same pattern density, the larger the aspect ratio, the higher the release force (hard to release), and the smaller the aspect ratio, the lower the release force (easy to release).

  FIG. 4A is a perspective view for explaining the definition of pattern density. The area of the concavo-convex pattern shown in FIG. 4A, that is, the area where the convex part 4 is formed (projection surface area shown below) is S2, and the upper surface 4a, side face 4b and convex part of the convex part 4 The pattern density is defined as S1 / S2, where S1 is the total area of the bottom surface 4c of the recesses between them. The area S1 is the total area of the portion in contact with the resist during imprinting in the pattern. The larger the S1 / S2, the greater the proportion of the portion that comes into contact with the resist and the greater the release force. In the pattern region, S1 and S2 are calculated by using the convex portion provided at the outermost edge as the end of the pattern region.

  FIG. 4B shows a pattern P1 having the same aspect ratio and a low pattern density, and a pattern P2 having a high pattern density. As shown in FIG. 4B, even in a pattern having the same aspect ratio, the larger the pattern density is, the larger the area of the portion that comes into contact with the resist is. Is low.

  In the present invention, usable molds are not particularly limited in size and structure. For example, the size of a reticle used in semiconductor lithography is 65 mm × 65 mm, 5 inches × 5 inches, A square shape of 6 inches × 6 inches or 9 inches × 9 inches and a circular counterbore applied to the center of the back surface is selected. The shape of the counterbore is determined in consideration of the gas permeability and the degree of flexure (bending rigidity) of the substrate in the portion thinned by the counterbore. For example, a substrate having a size of 6 inches × 6 inches, a substrate thickness of 6.35 mm, a counterbore diameter of 63 mm, and a counterbore part thickness of 1.1 mm can be used.

  The substrate preferably has a step structure on the surface so that the pattern formation region can be limited to the pedestal range. This is because the presence of this pedestal can limit the area where the template comes into contact with the wafer, that is, the area where the resin wets and spreads, to the surface of the pedestal (mesa) when the finished template is used in the device manufacturing process. This is because contact with the structure existing outside the pattern formation region of the substrate can be avoided. The height of the pedestal is preferably 1 to 1000 μm, more preferably 10 to 500 μm, and still more preferably 20 to 100 μm. In FIG. 1 and the like, the shape of the substrate shows only the pedestal portion.

(Mold manufacturing method)
The mold 1 can be manufactured, for example, by the following procedure. First, a resin liquid mainly composed of acrylic resin such as PHS (polyhydroxy styrene) type chemically amplified resin, novolac resin, PMMA (polymethyl methacrylate), etc. is applied onto a quartz substrate by spin coating or the like. Form a layer. Thereafter, the quartz substrate is irradiated with an electron beam (or laser light) while being modulated corresponding to the desired concavo-convex pattern, and the concavo-convex pattern is exposed on the surface of the resin layer. Thereafter, the resin layer is developed, and selective etching is performed by reactive in-etching (RIE) using the removed resin layer pattern as a mask to obtain a quartz mold having a predetermined uneven pattern.

  In the present embodiment, a case where a quartz mold is used will be described. However, the mold 1 is not limited to this, and an Si mold can also be used. In this case, the Si mold can be manufactured by the same method as the above-described quartz mold manufacturing method.

"Nanoimprint method and patterned substrate manufacturing method"
Next, an embodiment of the nanoimprint method will be described.

  The nanoimprint method of the present embodiment is a step of applying a resist on a nanoimprint substrate (substrate to be processed) using the mold 1 of the above-described embodiment, and the mold 1 is applied to the surface of the nanoimprint substrate on which a resist solution is applied. A pressing step for pressing, a curing step for curing the resist solution, and a release step for releasing the mold 1 from the cured resist film are included in this order.

(Imprint substrate)
Here, the imprint substrate 10 is a substrate to be processed onto which the uneven pattern (main pattern) of the mold 1 is transferred. There is no restriction | limiting in particular about the board | substrate 10 used by this embodiment, According to the objective, it can select suitably. For example, Si wafers of 6, 8, 12, 18 inch size can be used.

Further, the size and thickness of the mold and the imprint substrate 10 can be selected as appropriate. However, at least one of the mold and the imprint substrate needs to have light transmittance.
Here, the light transmittance may be such that light for curing a photocurable resist material applied on the imprint substrate can be incident by 5% or more.

(Resist solution)
As described above, the mold used in the present invention includes a main pattern region and a non-main pattern region, but the non-main pattern region is flat and / or has a lower pattern density than the main pattern region and / or a non-main pattern. Since the region is composed of a dummy pattern having a flat and / or aspect ratio smaller than that of the main pattern region, the mold release force is small in shape. For this reason, the main pattern region having a higher release force tends to be the end of release. Therefore, in order to make the mold release end become the non-main pattern area, a resist having a release force larger than that of the other areas is arranged in a predetermined area in the non-main pattern area (area to be released).
Even if the release force is the same, when comparing the high pattern aspect and low adhesion area with the low pattern aspect (including no pattern) and high adhesion area, the latter is overwhelmingly defective ( Pattern peeling and peeling). This is considered to be because, even with the same release force, the pattern existing in the high pattern density region or the high aspect pattern is more likely to break due to local stress concentration at the root portion.

  Therefore, in the present invention, a plurality of resist solutions having different components and different release forces after curing are prepared. At least two kinds of a first resist solution having a relatively low release force after curing and a second resist solution having a relatively high release force after curing are prepared. Here, when the first resist solution and the second resist solution are compared, the release force after curing of the first resist solution is the second resist having a relatively low release force. It means that the release force after curing of the second resist solution, which is lower than the release force after curing of the solution, is higher than the release force after curing of the first resist solution. An area corresponding to the main pattern area is prepared by further preparing one or a plurality of resist liquids having a release force that is between the first resist solution and the release force after the second resist solution is cured. From at least a part of the area corresponding to the non-main pattern area, the release force is the lowest in the area corresponding to the main pattern area, and the release force is at least part of the area corresponding to the non-main pattern area. A plurality of resist solutions whose components change stepwise may be applied separately so as to increase.

  The method for differentiating the release force after curing of the resist solution includes a method for different elastic modulus after curing, and a free energy per unit area (resist at the interface between the cured resist film and the mold) And a method for differentiating the adhesion force between the film and the mold.

  As a method of adjusting the elastic modulus after curing of the resist solution, there is a method of adjusting the sensitivity of the high-sensitivity photopolymerization initiator contained in the resist solution or the content of the polyfunctional polymerizable compound. In addition, as a method for adjusting the free energy at the interface between the resist film after curing and the mold, there are a method for introducing a compound having an adsorbing group into the composition constituting the resist solution, and a method for adjusting the release agent content. Can be mentioned. The (surface) free energy at the interface between the resist film and the mold is a work necessary for peeling the resist film and the mold. The smaller the free energy, the easier the peeling. That is, the smaller the free energy, the smaller the adhesion between the resist film and the mold. Hereinafter, each method for adjusting the release force will be described.

<Free energy adjustment: adsorption group>
First, as one method for adjusting the free energy at the interface with the mold after the resist solution is cured, a method for introducing a compound having an adsorption group with the mold into the curable resin composition will be described. Examples of the adsorbing group include an amine structure, a phosphate ester structure, a nitrate ester structure, and a polyalkylene oxide structure. The compound may not contain a polymerizable group. Specific examples of the compound containing the adsorbing group include dimethylaminoethyl acrylate (Osaka Organic Chemical), N, N, N ″, N ″ -tetraisopropyldiethylenetriamine, N, N′-diisopropylethylenediamine (Tokyo Chemical Industry Co., Ltd.) Company), 2-acryloyloxyethyl acid phosphate (Kyoeisha Chemical Co., Ltd.) and the like. The addition amount of the compound having an adsorbing group is preferably 0.01 to 10%, more preferably 0.1% to 5% with respect to the mass of the composition constituting the resist solution. The compound having an adsorbing group in the resist solution may be one kind or plural kinds. The amount added is the total amount of the compound having the above-mentioned adsorbing group.

  When preparing a first resist solution having a relatively low release force after curing and a second resist solution having a relatively high release force after curing, the adsorbing groups in the second resist solution are prepared. What is necessary is just to make the addition amount of the compound to have more than the addition amount in a 1st resist liquid.

<Elastic modulus adjustment: photopolymerization initiator>
As one method for changing the elastic modulus after curing of the resist solution, a method for changing the sensitivity of the photopolymerization initiator contained in the resist solution will be described.
If the photopolymerization initiator having higher sensitivity than the photopolymerization initiator in the curable resist solution used as a reference is included, a higher elastic modulus can be obtained after curing.

  For example, when the standard curable resist solution contains Irgacure (registered trademark) 754 as a photopolymerization initiator, as an example of a photopolymerization initiator having higher sensitivity than Irgacure (registered trademark) 754, Irgacure ( Registered trademark) 379, Irgacure (registered trademark) 369, Irgacure (registered trademark) OXE01, Irgacure (registered trademark) OXE02, Irgacure (registered trademark) 907, and the like.

  When preparing a first resist solution having a relatively low release force after curing and a second resist solution having a relatively high release force after curing, photopolymerization contained in the second resist solution As the initiator, one having a sensitivity higher than that of the photopolymerization initiator contained in the resist solution having a relatively low releasing force may be used.

<Modulation of elastic modulus: polyfunctional polymerizable compound>
As one method for changing the elastic modulus after curing of the resist solution, a method for changing the blending amount of the polyfunctional polymerizable compound contained in the resist solution will be described.
If a resist solution comprising a composition containing a polyfunctional polymerizable compound in an amount larger than the blending amount of the polyfunctional polymerizable compound in the reference curable resist solution is used, it should exhibit a higher elastic modulus after curing. it can.

  Examples of polyfunctional polymerizable compounds include 1,6-hexanediol diacrylate (Kyoeisha Scientific Co., Ltd.), neopentyl glycol diacrylate (Nippon Kayaku), pentaerythritol triacrylate (Toagosei), trimethylolpropane triacrylate (Toagosei) and the like.

  When preparing a first resist solution having a relatively low release force after curing and a second resist solution having a relatively high release force after curing, the polyfunctionality contained in the second resist solution What is necessary is just to make content of a polymeric compound larger than content contained in the resist liquid with a relatively low mold release force.

<Free energy adjustment: Release agent>
As another method for adjusting the free energy at the interface with the mold after the resist solution is cured, there is a method of changing the content of the release agent in the resist solution.
Examples of the mold release agent include fluorine-based surfactants.

  When preparing a first resist solution having a relatively low release force after curing and a second resist solution having a relatively high release force after curing, a mold release agent is contained in the second resist solution. The amount may be less than the content in the first resist solution.

(Resist application)
As a method for applying the resist solution, a method in which a predetermined amount of droplets can be arranged at a predetermined position on the substrate or the mold by an ink jet method is used. When disposing resist droplets on the substrate, an ink jet printer or a dispenser may be used depending on the desired droplet amount. For example, when the amount of droplets is less than 100 nl (nanoliter), an ink jet printer is used, and when it is 100 nl or more, a dispenser is used.

  Examples of the ink jet head that discharges resist droplets from a nozzle include a piezo method, a thermal method, and an electrostatic method. Among these, a piezo method capable of adjusting an appropriate amount of liquid (amount per droplet disposed) and a discharge speed is preferable. Before disposing the resist droplets on the substrate, the droplet amount and discharge speed are set and adjusted in advance. For example, the appropriate amount of liquid may be increased at a position on the substrate corresponding to a region where the space volume of the concave / convex pattern of the mold is large, or may be decreased at a position on the substrate corresponding to a region where the spatial volume of the concave / convex pattern of the mold is small. It is preferable to adjust. Such adjustment is appropriately controlled according to the droplet discharge amount (the amount per discharged droplet). Specifically, when the droplet amount is set to 5 pl (picoliter), the droplet amount is controlled to be ejected five times to the same place using an inkjet head having a droplet ejection amount of 1 pl. . The amount of droplets can be obtained, for example, by measuring the three-dimensional shape of droplets discharged on the substrate under the same conditions in advance with a confocal microscope or the like and calculating the volume from the shape.

  After adjusting the droplet amount as described above, droplets are arranged on the substrate according to a predetermined droplet arrangement pattern. The droplet arrangement pattern is configured by two-dimensional coordinate information including a grid point group corresponding to the droplet arrangement on the substrate (see FIG. 5 and the like).

  FIG. 5 is a plan view schematically showing an example of an arrangement pattern of resist droplets on the nanoimprint substrate 10. For example, when the mold 1 shown in FIG. 1 is used and a part (corner part in FIG. 1) 5 of the non-main pattern region 3 of the mold 1 is set as a mold release termination scheduled part, as shown in FIG. In the region 15 on the nanoimprint substrate 10 corresponding to the part 5 to be a mold release termination scheduled portion in (i.e., facing when pressed), a resist solution having a relatively high release force after curing is disposed. In other areas including the pattern area 2, a resist solution having a relatively low release force after curing is disposed.

  The ink jet method has a mechanism capable of applying a plurality of different resist solutions. It is appropriately controlled so that two or more kinds of resist solutions can be arranged at arbitrary positions.

(Imprint method)
Before bringing the mold 1 and the resist solution applied onto the nanoimprint substrate into contact, it is preferable to reduce the residual gas by reducing the atmosphere of the mold 1 and the nanoimprint substrate to a reduced pressure or vacuum atmosphere. However, in a high vacuum atmosphere, the resist solution before curing is volatilized and it may be difficult to maintain a uniform film thickness. Therefore, a method of reducing the residual gas is preferably adopted by setting the atmosphere between the mold 1 and the substrate to a He atmosphere or a reduced pressure He atmosphere. Since He permeates the quartz substrate, the trapped residual gas (He) gradually decreases. Since it takes time to transmit He, it is more preferable to use a reduced pressure He atmosphere. The reduced pressure atmosphere is preferably 1 to 90 kPa, and particularly preferably 1 to 10 kPa.

  The mold 1 and the substrate coated with the resist solution are brought into contact with each other after they are aligned so as to have a predetermined relative positional relationship. An alignment mark is preferably used for alignment.

  The pressing pressure of the mold 1 is in the range of 100 kPa to 10 MPa. A higher pressure promotes the flow of the resist solution, and also promotes the compression of the residual gas, the dissolution of the residual gas in the resist solution, and the permeation of He in the quartz substrate, leading to an improvement in the removal rate of the residual gas. However, if the applied pressure is too strong, there is a possibility of damaging the mold 1 and the substrate when a foreign object is caught when contacting the mold. Therefore, the pressing pressure of the mold 1 is preferably 100 kPa or more and 10 MPa or less, more preferably 100 kPa or more and 5 MPa or less, and further preferably 100 kPa or more and 1 MPa or less. The reason why the pressure is set to 100 kPa or more is that when imprinting is performed in the atmosphere, when the space between the mold 1 and the substrate is filled with liquid, the pressure between the mold 1 and the substrate is pressurized at an atmospheric pressure (about 101 kPa). Because.

  After the mold 1 is pressed to form a resist solution layer (resist film), the resist is cured by exposure with light containing a wavelength that matches the polymerization initiator contained in the resist solution. As a method for peeling (releasing) the mold 1 from the cured resist film, one of the back surface or the outer edge portion of the mold 1 or the substrate 10 is held, and the other back surface or the outer edge portion is held. There is a method of relatively moving the holding part or the holding part on the back surface in the direction opposite to the pressing. Alternatively, a method may be used in which both or one of the mold 1 and the substrate 10 is sucked over the entire back surface with a vacuum chuck or the like, and the mold 1 and the substrate 10 are moved relative to each other in opposite directions.

(Concavity and convexity pattern forming method of the first embodiment)
A first embodiment of a concavo-convex pattern forming method using an imprint method will be described. In the first embodiment, the mold 1 shown in FIG. 1 and the nanoimprint substrate 10 shown in FIG. 5 are used. Here, as the resist solution, a resist solution (first resist solution) 12 having a relatively low release force after curing, and a resist solution (second resist solution) having a relatively high release force after curing. A case where 13 is used will be described.

  First, as shown in FIG. 5, as a coating process, the second resist solution 13 is disposed in the region 15 of the nanoimprint substrate 10, and the first resist solution 12 is disposed in the other region.

  Next, as a pressing step, as shown in FIG. 6 a, the mold 1 is brought close to at least the main pattern region 2 so as to face the region where the first resist solution 12 is applied, and pressed against the substrate 10. (B in FIG. 6).

  Thereafter, as a curing step, the resist solutions 12 and 13 are cured by irradiating light from the back side of the mold 1 (above the paper surface) in the state of FIG.

  Then, the mold 1 is released from the resist films 12 and 13 formed by curing. At this time, the resist film 12 having a small release force is released first, and the region 15 of the resist film 13 having a large release force becomes the final release end (see c in FIG. 6). The region 15 and the above-described part 5 of the mold 1 are the final mold release end, but the mold 1 region which is the final mold release end is a flat portion, so that mogging, peeling and the like hardly occur (d in FIG. 6). reference).

(Concavity and convexity pattern forming method of the second embodiment)
A second embodiment of the uneven pattern forming method using the imprint method will be described. In the second embodiment, the mold 21 shown in FIG. 7 is used which is different from the mold 1 of the first embodiment in the formation region of the main pattern region. FIG. 7 is a schematic view showing a plan view of the mold 21.
The mold 21 shown in FIG. 7 is formed by dividing the uneven pattern of the main pattern to be transferred into four regions 22. Other than the main pattern region 22 is a non-main pattern region 23, and all the non-main pattern regions 23 in the transfer region are formed flat.

  Also in this embodiment, as the resist solution, a resist solution (first resist solution) 12 having a relatively low release force after curing, and a resist solution (second resist solution) having a relatively high release force after curing. Resist solution) 13 is used. In the present embodiment, the final end of mold release in the mold 21 is a corner 25.

  First, as in the first embodiment, as shown in FIG. 5, as a coating process, the second resist solution 13 is disposed in the region 15 of the nanoimprint substrate 10 and the first resist solution is formed in other regions. 12 is arranged.

  Next, as a pressing step, as shown in FIG. 8 a, the mold 21 is brought close to at least the main pattern region 22 so as to face the region where the first resist solution 12 is applied, and pressed against the substrate 10. (B in FIG. 8).

  Thereafter, as a curing step, the resist solutions 12 and 13 are cured by irradiating light from the back side of the mold 21 (above the paper surface) in the state of FIG.

  Then, the mold 21 is released from the resist films 12 and 13 formed by curing. At this time, the resist film 12 having a small releasing force is released earlier, and the region 15 of the resist film 13 having a large releasing force becomes the final mold release end (see c in FIG. 8). Although the corner 15 of the region 15 and the corresponding mold 21 is the final mold release end, the corner 25 of the mold 21 is a flat portion, so that there is almost no mogging or peeling (see d in FIG. 8). .

(Concavity and convexity pattern forming method of the third embodiment)
A third embodiment of the uneven pattern forming method using the imprint method will be described. In the third embodiment, the same mold 21 as in the second embodiment is used, and as a resist solution, a resist solution (first resist solution) 12 having a relatively low release force after curing, and a cured solution A resist solution (second resist solution) 13 having a relatively high release force is used. On the other hand, in this embodiment, the final mold release end in the mold 21 is the mold center portion 26 in the non-main pattern region 23.

  First, as in the first embodiment, as shown in FIG. 9, as a coating process, the second resist solution 13 is disposed in the central region 16 of the nanoimprint substrate 10, and the first resist is formed in other regions. Liquid 12 is placed. The central region 16 is a region corresponding to the central portion 26 of the non-main pattern region 23 of the mold 21.

  Next, as a pressing step, as shown in FIG. 10a, the mold 21 is brought close to the mold so that the central portion 26 of the mold and the central region 16 coated with the second resist solution on the substrate face each other. (Fig. 10b).

  Thereafter, as a curing step, the resist solutions 12 and 13 are cured by irradiating light from the back side of the mold 21 (above the paper surface) in the state of FIG.

  Then, the mold 21 is released from the resist films 12 and 13 formed by curing. At this time, the resist film 12 having a small release force is released first, and the region 16 of the resist film 13 having a large release force becomes the final release end (see c in FIG. 10). Although the area 16 and the center part 26 of the corresponding mold 21 are the final mold release end, the center part 26 of the mold 21 is a flat part, so that there is hardly any mogging or peeling (see d in FIG. 10).

(Concavity and convexity pattern forming method of the fourth embodiment)
A fourth embodiment of the uneven pattern forming method using the imprint method will be described. In the fourth embodiment, a mold 31 shown in FIG. 11 having a different configuration of the non-main pattern region is used as the mold 21 of the above-described embodiment. FIG. 11 is a schematic view showing a plan view of the mold 31.
The mold 31 shown in FIG. 11 is formed by dividing the concave / convex pattern of the main pattern to be transferred into four regions 32. Other than the main pattern region 32 is a non-main pattern region 33. A dummy pattern 35 is formed in the mold center portion 37 of the non-main pattern region 33, and the other regions of the non-main pattern region 33 are formed flat. ing. As described above, here, the dummy pattern is a concavo-convex pattern (convex portion of the concavo-convex pattern) having a smaller pattern density and aspect ratio than the concavo-convex pattern of the main pattern (convex portion of the concavo-convex pattern).

  Also in this embodiment, as the resist solution, a resist solution (first resist solution) 12 having a relatively low release force after curing, and a resist solution (second resist solution) having a relatively high release force after curing. Resist solution) 13 is used. In the present embodiment, the final mold release end of the mold 31 is a mold center portion 37 in which the dummy pattern 35 of the non-main pattern region 33 is formed.

  First, as in the third embodiment, as shown in FIG. 12, as a coating process, the second resist solution 13 is disposed in the central region 17 of the nanoimprint substrate 10 and the first resist is formed in other regions. Liquid 12 is placed.

  Next, as a pressing step, as shown in FIG. 13a, the mold 31 is a mold in which at least the main pattern region 32 faces the region where the first resist solution 12 is applied and the dummy pattern 35 is formed. The central portion 37 is brought close to the central region 17 to which the second resist solution 13 is applied and pressed against the substrate 10 (b in FIG. 13).

  Thereafter, as a curing step, the resist solutions 12 and 13 are cured by irradiating light from the back side of the mold 31 (above the paper surface) in the state of FIG.

  Then, the mold 31 is released from the resist films 12 and 13 formed by curing. At this time, the central region 17 where the resist film 13 having a large release force is formed is released first from the resist film 12 having a small release force, and becomes the final end of the mold release (see c in FIG. 13). . The central region 17 of the resist film and the corresponding dummy pattern 35 (mold central portion 37) of the mold 31 become the final mold release end. The dummy pattern 35 has a low pattern density and aspect ratio compared to the concave / convex pattern of the main pattern region 32 of the mold 31 and can be easily released as a shape. (See d in FIG. 13).

(Concavity and convexity pattern forming method of the fifth embodiment)
A fifth embodiment of the uneven pattern forming method using the imprint method will be described. In the fifth embodiment, the mold 41 shown in FIG. 14 having a different configuration of the non-main pattern region is used as the mold 21 of the above-described embodiment. FIG. 14 is a schematic view showing a plan view of the mold 41.
The mold 41 shown in FIG. 14 is formed by dividing the uneven pattern of the main pattern to be transferred into four regions 42. Other than the main pattern region 42 is a non-main pattern region 43, a dummy pattern 45 is formed in the mold corner 48 of the non-main pattern region 43, and other regions of the non-main pattern region 43 are formed flat. ing. Here, the dummy pattern is also composed of a concavo-convex pattern (convex portion of the concavo-convex pattern) having a smaller pattern density and aspect ratio than the concavo-convex pattern of the main pattern (convex portion of the concavo-convex pattern).

  Also in this embodiment, as the resist solution, a resist solution (first resist solution) 12 having a relatively low release force after curing, and a resist solution (second resist solution) having a relatively high release force after curing. Resist solution) 13 is used. In the present embodiment, the final end of mold release in the mold 41 is a corner 48 where the dummy pattern 45 of the non-main pattern region 43 is formed.

  First, as in the first embodiment, as shown in FIG. 15, as a coating process, the second resist solution 13 is disposed in the corner region 18 of the nanoimprint substrate 10, and the first region is formed in other regions. A resist solution 12 is disposed.

  Next, as a pressing step, as shown in FIG. 16a, the mold 41 faces at least the main pattern region 42 to the region where the first resist solution 12 is applied, and the dummy pattern 45 is the second resist. It adjoins so that it may face the corner | angular area | region 18 to which the liquid 13 was apply | coated, and it presses on the board | substrate 10 (b of FIG. 16).

  Thereafter, as a curing step, the resist solutions 12 and 13 are cured by irradiating light from the back side of the mold 41 (above the paper surface) in the state of FIG.

  And as a mold release process, mold 41 is released from resist films 12 and 13 formed by hardening. At this time, the corner region 18 where the resist film 13 having a large release force is formed, which is released first from the resist film 12 having a small release force, is the final end of the mold release (see c in FIG. 16). ). The corner area 18 of the resist film and the corresponding dummy pattern 45 of the mold 41 become the final mold release end. Since the dummy pattern 45 has a low aspect ratio as compared with the concave / convex pattern of the main pattern region 42 of the mold 41 and can be easily released as a shape, it can suppress the occurrence of mogging, peeling, and the like. (See d in FIG. 16).

(Method for manufacturing patterned substrate)
Next, an embodiment of a method for producing a patterned substrate (mold duplicate) will be described. In the present embodiment, a duplicate of the mold 1 is manufactured using the above-described nanoimprint method using a quartz mold as a master.

  First, using the nanoimprint method, a pattern-transferred resist film is formed on one surface of the substrate. Next, dry etching is performed using the resist film having the pattern transferred as a mask to form a concavo-convex pattern corresponding to the concavo-convex pattern formed on the resist film on the substrate to obtain a substrate having a predetermined pattern.

  The dry etching is not particularly limited as long as it can form a concavo-convex pattern on the substrate, and can be appropriately selected according to the purpose. For example, ion milling, reactive ion etching (RIE), sputter etching, etc. Is mentioned. Among these, ion milling and RIE are particularly preferable.

  As described above, according to the method for manufacturing a patterned substrate of the present invention, the final end region at the time of mold release is a substrate flat portion or a dummy pattern having a pattern density lower than that of the main pattern and / or a low aspect ratio. By separately applying and controlling a plurality of resist solutions so as to form a part, it is possible to effectively suppress the occurrence of defects at the time of mold release, and it is possible to manufacture a patterned substrate with a high yield.

  Hereinafter, examples and comparative examples of the uneven pattern forming method using the imprint method of the present invention will be described.

  First, the steps and evaluation methods of the molds, nanoimprint substrates used in the examples and comparative examples, and the method of forming a concavo-convex pattern common to each example will be described.

<Mold>
As the mold substrate, a synthetic quartz substrate having an external shape of 6 inches in length, 6 inches in width, and 0.25 inches in thickness was used.
The substrate has a step structure on the surface so that the pattern formation region can be limited to the pedestal range. This pedestal has a height (step difference) of 20 μm, and a horizontal × vertical size of 33 × 26 mm. The back surface of the substrate is counterbored, and has a counterbore diameter of 63 mm and a counterbore thickness of 1.1 mm.
On the surface of the base of the synthetic quartz substrate, an electron beam resist was applied at a thickness of 60 nm, drawn with an electron beam, developed, and then dry-etched to form a mold having an uneven pattern.

  17 and 18 are plan views schematically showing the pedestal portions of the molds 101 and 111 used in this example and / or comparative example.

  First, the first mold 101 shown in FIG. 17 will be described. The surface of the first mold 101 (the surface of the pedestal portion) is composed of a main pattern region 102 on which a concavo-convex pattern to be transferred is formed and a non-main pattern region 103 other than that. A dummy pattern 104 for adjusting the releasing force is provided in a part 105 of the area 103, and a blank area (flat area) having no pattern is formed except for the part 105 where the dummy pattern 104 of the non-main pattern area 103 is formed.

  Four main pattern regions 102 are provided in the transfer region, and one mold has a pattern for four chips. A line & space pattern having a width of 30 nm, a pitch of 60 nm, and a height of 60 nm is provided as a main pattern in one chip (one main pattern region 102), and a non-main pattern between the main pattern regions 102 at the center in the transfer region. A line & space pattern having a width of 50 nm, a pitch of 100 nm, and a height of 60 nm was provided as a dummy pattern 104 in the region 103. At this time, the aspect ratio (height / width) of the convex part (line) of the main pattern is 60/30, and the aspect ratio (height / width) of the convex part (line) of the dummy pattern is 60/50. The aspect ratio of the dummy pattern is smaller than the aspect ratio of the main pattern.

  Next, the second mold 111 shown in FIG. 18 will be described. The surface of the second mold 111 (the surface of the pedestal portion) is composed of a main pattern region 112 on which a concavo-convex pattern to be transferred is formed and a non-main pattern region 113 other than that. A dummy pattern different from the concavo-convex pattern to be transferred is provided in a portion 115 of the region 113, and a blank region (flat region) having no pattern other than the portion 115 where the dummy pattern 114 of the non-main pattern region 113 is formed.

Four main pattern areas 112 are provided in the transfer area, and one mold has a pattern for four chips. A line and space pattern having a width of 30 nm, a pitch of 60 nm, and a height of 60 nm is provided as a main concavo-convex pattern in one chip (one main pattern region 112), and a non-main portion between the main pattern regions 112 is formed at the center in the transfer region. A dot pattern having a diameter of 20 nm, a pitch of 40 nm, and a height of 60 nm was provided as a dummy pattern 114 in the pattern region 113.
At this time, the aspect ratio (height / width) of the convex portion (line) of the main pattern is 60/30, and the aspect ratio (height / width (diameter)) of the convex portion (dot) of the dummy pattern is 60/30. 20, the aspect ratio of the dummy pattern is larger than the aspect ratio of the main pattern.

<Nanoimprint substrate (substrate to be processed)>
A 12-inch Si wafer was used as the nanoimprint substrate.

<Resist solution>
The resist solution used in each example and comparative example was composed of the raw materials described in Tables 1 to 6 below, which were summarized for each example and comparative example. In Tables 1 to 6, the raw material of the resist solution dropped onto the substrate region (denoted as “dummy”) corresponding to the dummy pattern region of each example and the region corresponding to the other region (denoted as “main”) Respectively.

<Application of resist solution>
Application of the resist solution (arrangement of resist droplets) was performed using a tritech inkjet device stage jet. Two or more inkjet heads and a resist solution tank are mounted so that two or more types of resist solution and fat can be disposed in advance. An alignment mechanism using an optical microscope is provided, and a desired droplet can be arranged at a desired position on the wafer with reference to an arbitrary position on the wafer (here, the nanoimprint substrate).

<Nanoimprint>
After applying the resist solution on the nanoimprint substrate, the mold is pressed against the resist solution application surface of the nanoimprint substrate in a He reduced pressure atmosphere, and after the resist solution is sufficiently filled between the mold and the substrate, the peak wavelength is about 370 nm. The resist solution was cured by irradiation with UV light having an irradiation intensity of 2.5 W / cm ² for 20 seconds. Then, while holding the outer edge of the mold and holding the back side of the nanoimprint substrate with a vacuum chuck, the mold outer edge holding part and the substrate back side holding part are peeled by moving relative to each other in the opposite direction. It was.

<Determination of mold release end position>
From the mold release surface, the end position of the mold release was observed with a CCD camera, and it was determined whether the mold end was a dummy pattern or a main pattern.

<Determining the presence or absence of mold release defects>
The vicinity of the mold release end position was evaluated for the cured resin pattern after peeling with an optical microscope and a scanning electron microscope (SEM). When there was a pattern formation failure area, it was determined that there was a defect, and when there was no pattern formation, it was determined that there was no defect.

<Comprehensive evaluation>
Based on the above determination results, comprehensive evaluation was performed.
Good (A) when the mold release end position is a dummy pattern and no mold release defect in the vicinity of the mold release end, Impossible when the mold release end position is a dummy pattern and there is a mold release defect near the mold release end (B ), When the mold release end position is the main pattern and there is a mold release defect near the mold release end, it was evaluated as defective (C).

  Each Example and Comparative Example were imprinted according to the procedure described above, and were evaluated and evaluated.

(Examples 1-1, 1-2, 1-3, and 1-4)
In the nanoimprint substrate using the first mold 101 described above, the region corresponding to the dummy pattern region (described as “dummy” in Table 1 and the same in Tables 2 to 6. This substrate region is described below. And other regions (described as “main” in Table 1 and the same in Tables 2 to 6. This substrate region is hereinafter referred to as “main”). Each resist solution using the resist raw materials described in Table 1 was placed. Table 1 shows, for Examples 1-1, 1-2, 1-3, and 1-4, a dummy and a main resist material applied to the main (unit in the table is mass%), a release end position, and a release end defect. And a comprehensive evaluation. In these examples, the resist solution used for the dummy was one having a higher mold release force after curing than the resist solution used for the main. The resist solution applied to the dummy contains a compound having a predetermined adsorbing group, and the resist solution used for the main does not contain a compound having a predetermined adsorbing group. In Examples 1-1 to 1-4, resist solutions containing compounds containing different adsorbing groups were applied to the dummy areas.
As shown in Table 1, in all of Examples 1-1 to 1-4, the release end position was a dummy pattern region, and no defect occurred at the release end.

(Comparative Example 1-1)
As in Example 1, the first mold 101 described above was used, and in the nanoimprint substrate, a dummy region, a main region which is the other region, and a resist solution made of the resist material described in Table 2 were respectively used. Arranged. As shown in Table 2, in this comparative example, a resist solution having the same component was used for the dummy area and the main area.

(Comparative Examples 1-2, 1-3, 1-4, 1-5, 1-6)
Using the second mold 111 described above, in the nanoimprint substrate, the respective resist solutions using the resist raw materials described in Table 2 were arranged in the dummy region and the main region. As shown in Table 2, Comparative Example 1-2 uses resist solutions having the same components in the dummy area and the main area as in Comparative Example 1-1, and Comparative Examples 1-3 to 1-6 have different adsorptions. A resist solution containing a compound containing a group was applied to the dummy region, and a resist solution not containing a compound containing an adsorbing group was applied to the main region.

Table 2 summarizes the resist raw material applied to the dummy region and the main region, the release termination position, the release termination defect, and the overall evaluation for Comparative Examples 1-1 to 1-6.

  As shown in Table 2, as in Comparative Example 1-1, when the same resist solution was applied to the dummy region and the main region using the same mold 101 as the example, the mold release end position became the main pattern region, In addition, a defect occurs at the mold release end. Further, as in Comparative Examples 1-2 to 1-6, when a mold 111 having a concavo-convex pattern having a higher aspect ratio than the main concavo-convex pattern is used as a dummy pattern, the resist solution is separately applied to the dummy region and the main region. Even if it is not (Comparative Example 1-2) or if it is separately applied (Comparative Examples 1-3 to 1-6), the mold release end position is a dummy region. A defect occurred.

(Examples 2-1 and 2-2, Comparative Example 2-1)
On the nanoimprint substrate, the same procedure as in Example 1-1 was performed, except that the components of the resist solution arranged in the dummy region and the main region were those described in Table 3, respectively.
In these examples, the resist solution used in the dummy area was higher in the mold release force after curing than the resist liquid used in the main area. As the resist solution applied to the dummy region, a resist solution having a higher content of the multi-sensitive compound than the resist solution applied to the main region was used.

(Comparative Examples 2-2, 2-3, 2-4)
The second mold 111 was used, and the same procedure as in Example 2-1 was performed except that the components of the resist solution arranged in the dummy region and the main region were those described in Table 3, respectively.

Table 3 shows the resist raw material applied to the dummy region and the main region, the elastic modulus after curing (standardized elastic modulus), and the release for Examples 2-1 and 2-2 and Comparative Examples 2-1 to 2-4. It summarizes the termination position, mold termination defects and comprehensive evaluation. The elastic modulus was measured by a nanoindentation method using AFM (Atomic Force Microscope). The elastic modulus was divided by the highest elastic modulus in all the examples and comparative examples, specifically, the elastic modulus of the resist arranged in the dummy of Example 3-3 (= the dummy of Comparative Example 3-5) ( It is expressed as a normalized elastic modulus.

As shown in Table 3, in Examples 2-1 and 2-2, the release end position was a dummy pattern region, and no defect occurred at the release end.
As shown in Table 3, when the same resist solution was applied in the dummy area and the main area using the same mold 101 as in Comparative Example 2-1, the mold release end position became the main pattern area, In addition, a defect occurred at the mold release end. Further, as in Comparative Examples 2-2 to 2-4, when the mold 111 having a concavo-convex pattern having a higher aspect ratio than the main concavo-convex pattern is used as a dummy pattern, the resist solution is separately applied to the dummy region and the main region. Although the release end position is a dummy area both in the case where it is not applied (Comparative Example 2-2) and in the case where it is separately applied (Comparative Example 2-3, 2-4), a defect occurs in the release end. It was.

(Examples 3-1, 3-2, 3-3)
Example 1 was the same as Example 1-1 except that the components of the resist solution arranged in the dummy pattern, the dummy region, and the main region were those described in Table 4, respectively.
In these examples, the resist solution used for the dummy was one having a higher mold release force after curing than the resist solution used for the main. The resist solution applied to the dummy contains a polymerization initiator that is more sensitive than the resist solution applied to the main region.

Table 4 shows, for Examples 3-1, 3-2, and 3-3, the dummy, the resist material applied to the main, the elastic modulus after curing (standardized elastic modulus), the release end position, the release end defect, and A comprehensive evaluation.

  As shown in Table 4, in each of Examples 3-1 to 3-3, the release end position was a dummy pattern region, and no defect occurred at the release end.

(Comparative Example 3-1)
Example 3 was the same as Example 3 except that the components of the resist solution arranged in the dummy pattern, the dummy region, and the main region were those described in Table 5, respectively.

(Comparative Examples 3-2, 3-3, 3-4)
The second mold 111 was used, and the same procedure as in Example 3-1 was performed except that the components of the resist solution arranged in the dummy region and the main region were those described in Table 5, respectively.

Table 5 shows, for Comparative Examples 3-1 to 3-4, the resist material applied to the dummy region and the main region, the elastic modulus after curing (standardized elastic modulus), the mold release end position, the mold release end defect, and the comprehensive evaluation. Are summarized.

  As shown in Table 5, when the same resist solution was applied in the dummy area and the main area using the same mold 101 as in Comparative Example 3-1, the mold release end position became the main pattern area, In addition, a defect occurs at the mold release end. Further, as in Comparative Examples 3-2 to 3-6, when a mold 111 having a concavo-convex pattern having a higher aspect ratio than the main concavo-convex pattern is used as a dummy pattern, the resist solution is separately applied to the dummy region and the main region. Even if it is not (Comparative Example 3-2), or even if it is painted separately (Comparative Examples 3-3 to 3-5), the mold release end position is a dummy region. A defect occurred.

(Example 4, Comparative example 4-1)
Example 1 was the same as Example 1-1 except that the components of the resist solution arranged in the dummy region and the main region were those listed in Table 6, respectively.
In Example 4, the resist solution used for the dummy area was higher in mold release force after curing than the resist liquid used for the main area. A resist solution containing a release agent (fluorine surfactant) was used as the resist solution applied to the main region, and a resist solution containing no release agent was used as the resist solution applied to the dummy region.
On the other hand, as Comparative Example 4-1, the resist solution used for the dummy region and the main region had the same composition, and both included a release agent.

(Comparative Examples 4-2 and -3)
The second mold 111 was used, and the same procedure as in Example 4 was performed except that the components of the resist solution arranged in the dummy region and the main region were those described in Table 6, respectively.

Table 6 shows, for Example 4 and Comparative Examples 4-1 to 4-3, the resist raw material applied to the dummy region and the main region, the elastic modulus after curing (standardized elastic modulus), the release end position, and the release end. It summarizes defects and overall evaluation.

As shown in Table 6, in Example 4, the release end position was a dummy pattern region, and no defect occurred at the release end.
As shown in Table 6, as in Comparative Example 4-1, when the same resist solution was applied to the dummy area and the main area using the same mold 101 as the example, the mold release end position became the main pattern area, In addition, a defect occurred at the mold release end. Further, as in Comparative Examples 4-2 and 4-3, when a mold 111 having a concavo-convex pattern having a higher aspect ratio than the main concavo-convex pattern is used as a dummy pattern, the resist solution is separately applied to the dummy region and the main region. In both cases (Comparative Example 4-2) and the case of separate coating (Comparative Example 4-3), the mold release end position was a dummy region, but a defect occurred in the mold release end.

1, 21, 31, 41, 101, 111 Molds 2, 22, 32, 42, 102, 112 Main pattern regions 3, 23, 33, 43, 103, 113 Non-main pattern regions 4 Convex and concave projections 5, 25 , 26, 37, 48 Mold release termination region 10 Substrate to be processed (nanoimprint substrate)
12 First resist droplet 13 Second resist droplet 15, 16, 17, 18 Resist film release termination region 104, 114 Dummy pattern

Claims (9)

An application step of disposing a photocurable resist solution at a desired position on the nanoimprint substrate; and a pressing step of pressing a mold having a fine uneven pattern on the surface of the nanoimprint substrate on the surface on which the resist solution is applied; A concavo-convex pattern forming method comprising: a curing step of curing the resist solution to form a resist film; and a mold release step of releasing the mold from the resist film,
As the mold, a main pattern region formed with a concavo-convex pattern to be transferred, and a dummy pattern or a flat surface comprising a concavo-convex pattern having a smaller pattern density or aspect ratio than the concavo-convex pattern adjacent to the main pattern region. Using a surface with a non-main pattern area,
As the resist solution, a plurality of resist solutions having different components and different release forces after curing are prepared,
In the coating step, a resist solution having a relatively low release force after curing is disposed in a region corresponding to the main pattern region on the surface of the nanoimprint substrate, and the nonimprint substrate surface A concavo-convex pattern forming method in which a resist solution having a relatively high release force after curing is disposed in at least a part of a region corresponding to a main pattern region.   2. The resist solution having a relatively high releasing force is a composition having an elastic modulus after curing larger than an elastic modulus after curing of the resist solution having a relatively low releasing force. The uneven | corrugated pattern formation method of description.   The sensitivity of the photopolymerization initiator contained in the resist solution having a relatively high release force is higher than the sensitivity of the photopolymerization initiator contained in the resist solution having a relatively low release force. Item 3. The method for forming an uneven pattern according to Item 2.   The content of the polyfunctional polymerizable compound in the resist solution having a relatively high releasing force is larger than the content of the polyfunctional polymerizable compound in the resist solution having a relatively low releasing force. The uneven | corrugated pattern formation method of description.   As the resist solution having a relatively high mold release force, the free energy per unit area at the interface with the mold after curing is the interface with the mold after curing the resist solution with a relatively low mold release force. The uneven | corrugated pattern formation method of Claim 1 using the composition used as a thing smaller than the free energy per unit area in. As the resist solution having a relatively high releasing force, at least one photocurable resin component having at least one of an amine structure, a phosphate ester structure, a sulfate ester structure, and a polyalkylene oxide structure is used. Using the composition containing above,
As a resist solution having a relatively low release force, the content of the photocurable resin component having the structure is a photocurable resin component having the structure in the resist solution having a relatively high release force. The uneven | corrugated pattern formation method of Claim 2 or 5 using a composition smaller than content.   6. The resist solution having a relatively high release force is a composition having a release agent content smaller than the release agent content in the resist solution having a relatively low release force. The uneven | corrugated pattern formation method of description. Preparing the plurality of resist solutions by gradually changing one or more components;
In the coating step, the plurality of resist solutions are stepwise from the region corresponding to the main pattern region to at least part of the region corresponding to the non-main pattern region on the surface of the nanoimprint substrate. The uneven | corrugated pattern formation method of any one of Claim 1 to 7 arrange | positioned so that it may change. A resist film having a concavo-convex pattern transferred thereon is formed on the surface of the nanoimprint substrate, which is a substrate to be processed, by the concavo-convex pattern forming method according to claim 1,
A method of manufacturing a patterned substrate, wherein the substrate to be processed is etched using the resist film as a mask, and a concavo-convex pattern corresponding to the concavo-convex pattern transferred to the resist film is formed on the substrate to be processed.