JP2013202900A - Mold and method of manufacturing the same, nanoimprint method, and method of manufacturing patterned substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce defects of a resist pattern in nanoimprinting using a mold having a pattern including different pattern sizes.SOLUTION: A mold 1 for nanoimprinting which has fine uneven patterns, including a plurality of recessed portions differing in width, formed on a surface has recessed-portion surface energy set to be higher in division regions R1, R2, and R3 belonging to large-width sections, a pattern region R where the uneven pattern is formed being divided into the division regions R1, R2, and R3 according to prescribed sections of widths of the recessed portions.

Description

  The present invention relates to a mold having a predetermined concavo-convex pattern on its surface, a manufacturing method thereof, a nanoimprinting method, and a manufacturing method of a patterned substrate.

  In nanoimprinting, a mold (generally referred to as a mold, stamper, or template) in which a concavo-convex pattern is formed is pressed against the resist applied on the workpiece (imprinting), and the resist is mechanically deformed or fluidized to make fine patterns. This is a technology that precisely transfers a pattern to a resist film. Once a mold is made, it is economical because nano-level microstructures can be easily and repeatedly molded. In addition, it is a transfer technology with little harmful waste and emissions, so it is expected to be applied in various fields in recent years. (Patent Document 1).

  For example, when a semiconductor device is manufactured by nanoimprint, it is expected that a resist pattern including a plurality of pattern sizes can be formed at the same time, and the manufacturing process can be simplified.

JP 2011-206981 A

  However, if the mold pattern includes patterns of significantly different pattern sizes (particularly the width of the recesses) such as nm size (for example, 1 nm to several hundred nm) and μm size (for example, 1 μm to several hundred μm), Since the resist filling property and the release behavior when the mold is peeled off from the resist are greatly different depending on the pattern sizes, it may be difficult to simultaneously form resist patterns having these pattern sizes.

  The present invention has been made in view of the above problems, and in a nanoimprint using a mold having patterns having different pattern sizes, a mold capable of reducing the occurrence of defects in a resist pattern, a manufacturing method thereof, and a nanoimprint It is intended to provide a method.

  Furthermore, an object of the present invention is to provide a manufacturing method capable of improving productivity in manufacturing a patterned substrate.

In order to solve the above problems, the mold according to the present invention is:
In the mold for nano-imprint in which a fine uneven pattern including a plurality of recesses having different widths is formed on the surface,
Regarding the divided region of the pattern region in which the concave / convex pattern is formed and divided according to the predetermined division with respect to the width of the concave portion, the divided region belonging to the larger width portion has a higher surface energy in the concave portion. It is what.

  In the present specification, the “predetermined section” for the width of the recess means classification of the recess based on the size of the width of the recess.

And in the mold according to the present invention, the surface energy in the divided region belonging to the section where the width of the recess is less than 250 nm is less than 20 mJ / mm ² ,
The surface energy in the divided region width of the recess is in segments less than 750nm or 250nm is less than 20 mJ / mm ² or more 40 mJ / mm ^2,
The surface energy in the divided region belonging to the section where the width of the recess is 750 nm or more is preferably 40 mJ / mm ² or more.

In this case, the surface energy in the divided region belonging to the section where the width of the recess is less than 50 nm is preferably less than 15 mJ / mm ² and / or the divided region belonging to the section where the width of the recess is 1000 nm or more. It is preferable that the surface energy in is 70 mJ / mm ² or more.

  In the mold according to the present invention, it is possible to adopt a configuration in which at least a part of the pattern region has a release layer corresponding to the division to which the divided region belongs for each divided region.

The method for producing a mold for nanoimprinting according to the present invention includes:
Prepare a mold body with a fine concavo-convex pattern that includes a plurality of recesses with different widths on the surface,
Regarding the divided region of the pattern region in which the concave / convex pattern is formed and divided according to the predetermined division about the width of the concave portion, the divided region belonging to the larger width portion has a higher surface energy in the concave portion, The surface treatment is performed on at least a part of the pattern area with the processing content corresponding to the division to which the divided area belongs for each divided area.

In the method for producing a mold according to the present invention, the surface treatment is performed so that the surface energy in the divided region belonging to the section where the width of the recess is less than 250 nm is less than 20 mJ / mm ² and the width of the recess is 250 nm or more and less than 750 nm. intended to be located above the surface energy in the belonging divided region division and 20 mJ / mm ² or more 40 mJ / mm less than ^2, the surface energy in the divided regions included in each segment the width of the recess is 750nm or more 40 mJ / mm ² or more Preferably there is.

In this case, the surface treatment is preferably such that the surface energy in the divided region belonging to the section where the width of the recess is less than 50 nm is less than 15 mJ / mm ^2, and the section where the width of the recess is 1000 nm or more. The surface energy in the divided region to which it belongs is preferably set to 70 mJ / mm ² or more.

  Further, in the mold manufacturing method according to the present invention, the processing content is preferably that the release material is applied by an ink jet method while changing the release processing conditions according to the division to which the divided region belongs.

The nano-imprint method according to the present invention comprises:
Using the nanoimprint mold described above, the resist film applied on the substrate is pressed, the resist film is cured, and then the mold is peeled off from the resist film.

A method for producing a patterned substrate according to the present invention includes:
A resist film having a concavo-convex pattern transferred thereon is formed on a substrate to be processed by the nanoimprint method described above, and then etched using the resist film as a mask.

  According to the mold, the manufacturing method thereof, and the nanoimprint method according to the present invention, with respect to the divided region divided according to the predetermined division about the width of the concave portion of the mold pattern, the surface energy in the concave portion is higher in the divided region belonging to the larger width portion. By setting it high, it is possible to reduce the difference in behavior of resist filling property and pattern releasability in each of the recesses having different pattern sizes. As a result, it is possible to reduce the occurrence of resist pattern defects in nanoimprints using molds having patterns including different pattern sizes.

  Moreover, according to the manufacturing method of the patterned substrate which concerns on this invention, generation | occurrence | production of a pattern defect is reduced and a patterned substrate can be manufactured efficiently. As a result, productivity can be improved in the manufacture of the patterned substrate.

It is a schematic sectional drawing which shows the structure of the mold of embodiment. It is a schematic sectional drawing which shows 1 process of the manufacturing method of the mold of embodiment. It is a schematic sectional drawing which shows the resist film with a pattern defect.

  Hereinafter, although an embodiment of the present invention is described using a drawing, the present invention is not limited to this. In addition, for easy visual recognition, the scale of each component in the drawings is appropriately changed from the actual one.

"Mold and mold manufacturing method"
First, an embodiment of a mold and a method for manufacturing the mold will be described. FIG. 1 is a schematic cross-sectional view showing the mold of this embodiment.

<Mold>
The mold 1 according to the present embodiment is a divided region of a pattern region where a concavo-convex pattern is formed and divided according to a predetermined division with respect to the width W of the concave portion. The surface energy in the recess is high.

  There is no restriction | limiting in particular as a material of the mold 1, Although it can select suitably according to the objective, Any material of Si, Si oxide, Si nitride, quartz, a metal, and resin is suitable. As said metal, various metals, such as Ni, Cu, Al, Mo, Co, Cr, Ta, Pd, Pt, Au, or these alloys can be used, for example. Among these, Ni and Ni alloys are particularly preferable. Examples of the resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), triacetate cellulose (TAC), and a low melting point fluororesin.

<Uneven pattern>
The concavo-convex pattern (also referred to as a mold pattern) includes a plurality of concave portions respectively belonging to a plurality of sections having different pattern sizes (widths W of the concave portions). The uneven pattern is appropriately designed according to the shape to be transferred to the resist. For example, the width of the concave portion of the concave / convex pattern (the full width at half maximum in the concave portion), the depth of the concave portion, and the interval between the concave portions are, for example, 10 to 20000 nm, 20 to 200 nm, and 10 to 2000 nm, respectively. The shape of the concave portion and / or the convex portion of the concavo-convex pattern is, for example, a rectangular shape or a dot shape in plan view. In addition, the shape of the concave and / or convex portion of the concave / convex pattern is a shape in which a plurality of convex portions are combined at the apex or share some sides with a rectangular convex portion as a basic unit in plan view. There is also. In the embodiment, the concavo-convex pattern is formed near the center of the mold 1, but is not necessarily limited thereto. In addition, the area | region R in which the uneven | corrugated pattern is actually formed among the surface areas of the mold 1 is called a “pattern area”.

<Division area>
The divided region is a region divided based on the size of the width W of the concave portion in the pattern region R, that is, the section to which the concave portion in the region belongs. On the mold 1 of the present embodiment, for example, as shown in FIG. 1, the first divided region R1 of the section to which the concave portion having the largest width belongs, and the second divided region R2 of the section to which the concave portion having the next largest width belongs. And the third divided region R3 of the section to which the concave portion having the smallest width belongs. Note that the division into which the individual concave portions are distributed is appropriately set based on the configuration of the mold pattern, the accuracy of reducing the defects of the resist pattern, and the like. For example, if you want to increase the accuracy of reducing pattern defects, narrow the width range of the recesses applied to each category to classify the recesses in the mold pattern finely, or the mold pattern configuration is simple and the recesses are finely classified If it is not necessary to do so, the range of the width of the concave portion assigned to each section can be widened to roughly classify the concave portion. Further, when the mold pattern includes only concave portions having different widths within a limited range, one section may be assigned for each width.

  In each divided region R1, R2, and R3, the surface energy in the concave portion is set higher in the divided region belonging to the section having the larger width W. Therefore, in this embodiment, the surface energy in the recess in the first divided region is the highest, the surface energy in the recess in the second divided region is the next highest, and the surface energy in the recess in the third divided region is the lowest. .

  The control of the surface energy is not particularly limited as long as it is a surface treatment method capable of partially modifying the surface. For example, a dry process such as an ion implantation method or a wet process such as a coating method can be employed. Particularly in the case of a wet process, it is preferable to employ a method of applying a surface modifier by an ink jet method or a dispensing method. In addition, when applying droplets of the surface modifier on the substrate, an ink jet printer or a dispenser may be used depending on the desired droplet amount. For example, there are methods such as using an ink jet printer when the amount of droplets is less than 100 nl, and using a dispenser when the amount is 100 nl or more.

The surface energy suitable for the width of the concave portion belonging to each section is appropriately adjusted, but the concave portion belonging to the section having a larger width increases the surface energy. In particular, the surface energy in the divided region belonging to the section where the width of the recess is less than 250 nm is less than 20 mJ / mm ² , and the surface energy in the divided region belonging to the section where the width of the recess is not less than 250 nm and less than 750 nm is 20 mJ / mm. It is preferable that the surface energy is 40 mJ / mm ² or more in the divided region belonging to the section of mm ² or more and less than 40 mJ / mm ² and the width of the recess is 750 nm or more. Furthermore, in this case, it is preferable that the surface energy in the divided region belonging to the section where the width of the recess is less than 50 nm is less than 15 mJ / mm ² and / or belongs to the section where the width of the recess is 1000 nm or more. The surface energy in the divided region is preferably 70 mJ / mm ² or more.

<Mold manufacturing method>
On the other hand, FIG. 2 is a schematic cross-sectional view showing one step of the mold manufacturing method of the embodiment.

  The manufacturing method of the mold 1 of this embodiment prepares the mold main body 10 in which the fine uneven | corrugated pattern containing the several recessed part from which width differs is formed in the surface, and division | segmentation area | region R1, R2 of the pattern area | region in which the uneven | corrugated pattern was formed And R3, and the divided regions R1, R2, and R3 divided according to the predetermined division of the width of the concave portion, the divided regions R1, R2, and R3 so that the divided regions belonging to the larger width have higher surface energy in the concave portion. The surface treatment is performed on at least a part of the pattern region with the processing content corresponding to the division to which the divided regions R1, R2, and R3 belong for each of R2 and R3.

  The material of the mold body 10 is the same as that of the mold 1. In this embodiment, as an example, a case where a quartz mold having a concavo-convex pattern formed on a synthetic quartz substrate is described will be described.

The mold main body 10 is a member before the surface treatment is performed, and has the same uneven pattern as the uneven pattern of the mold 1 on the surface thereof. For example, the mold body 10 forms a photoresist film on the substrate surface on which the mold 1 is based, exposes a portion of the photoresist film corresponding to the mold pattern with an electron beam, and develops the exposed portion of the photoresist film. Formed by etching using the remaining photoresist as a mask,
<Resist patterning>
First, a synthetic quartz substrate having an outer shape of 6 inches in length and width and a thickness of 0.25 inch is prepared as a substrate to be a mold material. Subsequently, a resist is applied to the surface of the quartz substrate. A resist suitable for the patterning method described later is selected. That is, when an electron beam lithography apparatus is used for subsequent patterning, an electron beam resist is selected. When an ion beam lithography apparatus is used, an ion beam resist is selected. When a laser lithography apparatus is used, a photoresist is selected. If the selected resist is, for example, an electron beam resist, the resist film in a portion corresponding to the concavo-convex pattern is exposed with an electron beam, and the exposed resist film is removed by development, whereby the resist is patterned. A film made of an inorganic material such as chromium may be formed between the quartz substrate and the resist.

<Pattern patterning by etching>
By performing the dry etching process of the quartz substrate from the surface on which the resist is patterned by the method described above, the pattern formed on the resist is transferred to the quartz substrate. The etching process may be anisotropic etching (vertical etching), and for example, dry etching can be suitably used. Dry etching equipment includes inductively coupled (ICP) dry etching equipment, reactive ion (RIE) dry etching equipment, electron cyclotron resonance (ECR) dry etching equipment, microwave dry etching equipment, and parallel plate dry etching equipment. A helicon type dry etching apparatus or the like can be used.

The gas used for dry etching is appropriately selected according to the selected substrate material. For example, a gas containing a halogen group atom such as fluorine, chlorine, bromine (CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , SF ₆ , Cl ₂ , BCl ₃ , HC _l , HBr, I ₂ ) or a mixed gas may be used depending on the substrate material. Further, gas such as O ₂ , N ₂ , H ₂ , Ar, and He may be added for adjusting the etching shape and the resist selectivity.

On the other hand, when dry etching is performed using silicon as a substrate material, for example, a gas containing fluorine, chlorine, bromine or the like is preferably used. In addition, when dry etching is performed using aluminum, chromium, and an oxide or nitride thereof as a substrate material, it is preferable to use a gas containing chlorine. When dry etching is performed using a material containing SiO ₂ as a substrate material, it is preferable to use a gas containing fluorine, chlorine, or the like.

<Surface treatment method>
The surface treatment controls the surface energy on the uneven pattern of the mold body 10. In the present embodiment, the surface treatment is, for example, a mold release process in which a mold release material as a surface modifier is applied. In this embodiment, in order to form a release layer in a desired divided region on the mold body 10, the release process is performed by applying a release material only to the desired divided region using, for example, an ink jet (hereinafter, IJ) method. Is done. Although it does not restrict | limit especially as a mold release material, A fluorine-type resin, a hydrocarbon type lubricant, a fluorine-type lubricant, a fluorine-type silane coupling agent, etc. can be used. Regarding the processing content of the surface treatment, the mold release processing conditions are appropriately changed according to the division to which the divided region belongs. That is, the processing content is determined depending on how the surface energy of each divided region is to be controlled. For example, in the present embodiment, the release material 2 capable of reducing the surface energy is applied to the third divided region R3 where the surface energy is desired to be lowest (FIG. 2a). Next, a release material 3 capable of lowering the surface energy is applied to the divided region R2 (FIG. 2b). In addition, when the surface energy in the state which is not surface-treated enters the range of the surface energy suitable for the division | segmentation of the division area, it is not necessary to perform surface treatment with respect to the division area. That is, in the present invention, it is important that a surface energy state suitable for each section is realized in each divided region regardless of the presence or absence of the surface treatment. In addition to changing the release material, the change of the release treatment condition includes change of the release time and the dilution degree of the release material.

<Effect>
The effects of the present invention will be described below.

  In the problem of the invention, when the mold pattern includes patterns of pattern sizes that are greatly different, the behavior of resist filling and pattern releasability varies greatly depending on the pattern size. It was pointed out that it may be difficult to form at the same time. This is because, when the release layer is formed under uniform conditions over the entire surface of the mold 1, pattern defects are likely to occur at the recesses having a large width, and when the release layer is not formed at all, the pattern is formed at the recesses having a small width. This is because defects tend to occur.

  Specifically, it is as follows. FIG. 3 is a schematic cross-sectional view showing a resist film having a pattern defect. In particular, FIG. 3a is a schematic view when the resist 5 is applied on the substrate 4 and imprinted by the mold 1, and FIG. 3b is a schematic view showing pattern defects that may occur when the mold 1 is peeled from the resist 5. . The release layer is generally composed of a release material that functions to lower the surface energy in order to reduce the release force (force required when peeling the mold from the resist). However, the reduction of the surface energy of the recess means that the surface tension acting on the interface between the mold 1 and the resist 5 is also reduced, and the action of positively flowing the resist to the recess of the mold pattern is suppressed. In this case, it is possible to ensure the action of positively flowing into the concave portion by capillary action in the concave portion having a small width (nm size pattern), but such a concave portion having a large width (pattern having a size of um size or more). Since the action is weakened, bubbles 6 remain in the recesses during imprinting, and for example, unfilled defects 7a are likely to occur (FIGS. 3a and 3b).

  On the other hand, when the release layer is not formed, the contact area per unit area in the recess of the mold pattern is increased in the recess having a small width, and the interaction between the mold 1 and the resist 5 is increased. As a result, the resist remains in the recess of the mold pattern and is lost (7b in FIG. 3b), the resist pattern is extended (7c in FIG. 3b), or the resist pattern is bent (7d in FIG. 3b). As a result, a release failure defect is likely to occur.

  In this regard, in Patent Document 1, in order to improve the filling property of the resist, a predetermined release layer is formed on the side surface and the bottom surface of the concave portion of the mold pattern, and the release layer made of another material is formed on the upper surface of the convex portion. And the advantage that the mold release property is different between the side surface and bottom portion of the pattern and the convex portion and the mold release starts from the convex portion is described. However, the release from the convex portion means that the resist is pulled inside the mold pattern, and in this case, the dimensional accuracy of the resist pattern is lowered or the resist pattern is destroyed. There is a fear. Further, in Patent Document 1, since the contents of the surface treatment are the same when viewed for each recess, the invention of Patent Document 1 cannot solve the problem of mold patterns including patterns having different pattern sizes.

  On the other hand, in the present invention, by setting the surface energy in the concave portion higher in the divided region belonging to the section having a larger width, in the divided region belonging to the section having a larger width, the resist is actively flowed to the concave portion of the mold pattern. It is possible to suppress an increase in the interaction between the mold 1 and the resist 5 in the divided region belonging to the section having a small width while ensuring. In other words, according to the present invention, it is possible to bring the behavior of resist filling and pattern releasability close to each other in different pattern sizes.

  As described above, according to the present invention, it is possible to reduce the occurrence of resist pattern defects in nanoimprints using molds having patterns including different pattern sizes.

"Nanoimprint method"
Next, an embodiment of the nanoimprint method will be described.

  In the nanoimprint method of the present embodiment, using the mold 1 of the above-described embodiment, a resist is applied onto the nanoimprint substrate, the mold 1 is pressed against the surface of the nanoimprint substrate on which the resist is applied, and the resist is cured. The post mold 1 is released from the resist.

<Imprint substrate>
For the Si mold, a quartz substrate is preferable in order to enable exposure to a resist. The quartz substrate is appropriately selected according to the purpose without particular limitation as long as it has light transparency and a thickness of 0.3 mm or more. For example, a quartz substrate surface coated with a silane coupling agent, an organic layer made of a polymer for improving adhesion to a resist, and the like, Cr, W, Ti, Ni, Ag, A laminate of metal layers made of Pt, Au, etc., a laminate of metal oxide films made of CrO ₂ , WO ₂ , TiO ₂ etc. on a quartz substrate, and the surface of the laminate with a silane coupling agent For example, a coated one. The thickness of the organic material layer, metal layer or metal oxide film layer is usually 30 nm or less, preferably 20 nm or less. This is because when the thickness exceeds 30 nm, the UV transmittance is lowered and the resist is hard to be cured.

  On the other hand, the shape, structure, size, material and the like of the substrate for the quartz mold are not particularly limited, and can be appropriately selected according to the purpose. For example, in the case of an information recording medium, the shape is a disk shape. The structure may be a single layer structure or a laminated structure. The material can be appropriately selected from those known as substrate materials, and examples thereof include silicon, nickel, aluminum, glass, and resin. These board | substrate materials may be used individually by 1 type, and may use 2 or more types together. The substrate may be appropriately synthesized or a commercially available product may be used. Moreover, what coat | covered the surface with the silane coupling agent may be used. There is no restriction | limiting in particular as thickness of a board | substrate, Although it can select suitably according to the objective, 0.05 mm or more is preferable and 0.1 mm or more is more preferable. If the thickness of the substrate is less than 0.05 mm, the substrate may be bent when the substrate and the mold are in close contact with each other, and a uniform contact state may not be ensured.

<Resist>
The resist is not particularly limited, but in this embodiment, for example, a photopolymerization initiator (about 2% by mass) and a fluorine monomer (0.1 to 1% by mass) are added to a polymerizable compound. A resist can be used. Although the surface energy differs depending on the presence or absence of the fluorine monomer in the resist, it is preferable that fluorine is contained.

<Resist application method>
The resist coating method is not particularly limited, and a known method such as a spin coating method can be adopted. In addition, a method that can dispose a predetermined amount of droplets at a predetermined position on a substrate or a mold, such as an inkjet method or a dispensing method, can also be used.

  When disposing the resist droplets on the substrate, an ink jet printer or a dispenser may be used depending on the desired droplet amount. For example, there are methods such as using an ink jet printer when the amount of droplets is less than 100 nl, and using a dispenser when the amount is 100 nl or more.

<Imprint method>
Before bringing the mold 1 into contact with the resist, the residual gas is preferably reduced by reducing the atmosphere between the mold 1 and the nanoimprint substrate to a reduced pressure or vacuum atmosphere. However, in a high vacuum atmosphere, the resist 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 permeate 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.

  As described above, since the mold of the present invention is used in the nanoimprint method of the present embodiment, it is possible to reduce the occurrence of resist pattern defects in nanoimprint using molds having patterns having different pattern sizes. Become.

"Method for manufacturing patterned substrate"
Next, an embodiment of a method for producing a patterned substrate (for example, a mold duplicate) will be described. In this embodiment, for example, using a silicon mold as a master, a duplicate of the mold is manufactured using the nanoimprint method described above.

  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.

  On the other hand, when the substrate has a laminated structure and includes a metal layer on the surface, dry etching is performed using the resist film as a mask, and the concavo-convex pattern corresponding to the concavo-convex pattern formed on the resist film is applied to the metal. Then, the substrate is further dry-etched using the metal thin layer as an etch stop layer to form a concavo-convex pattern 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.

  The ion milling method is also called ion beam etching and introduces an inert gas such as Ar into an ion source to generate ions. This is accelerated through the grid, and collides with the sample substrate for etching. Examples of the ion source include a Kaufman type, a high frequency type, an electron impact type, a duoplasmatron type, a Freeman type, an ECR (electron cyclotron resonance) type, and the like.

  Ar gas can be used as a process gas in the ion milling method, and fluorine-based gas or chlorine-based gas can be used as an etchant for RIE.

  As described above, according to the method for manufacturing a patterned substrate of the present invention, since the substrate is etched using the resist film in which the occurrence of unfilled defects is reduced as a mask, the occurrence of pattern defects is reduced and the efficiency is increased. Well patterned substrates can be manufactured. As a result, productivity can be improved in the manufacture of the patterned substrate.

  Examples of the method for producing a master mold according to the present invention are shown below.

<Example>
First, a synthetic quartz substrate having a length and width of 6 inches and a plate thickness of 0.25 inches was prepared as a base substrate for an imprint mold. Next, a positive electron beam resist (ZEP520 / manufactured by Nippon Zeon Co., Ltd.) is coated to a thickness of 100 nm on the silicon wafer, and the dose is 20 μC / cm ² using an electron beam drawing apparatus (manufactured by JEOL Ltd.). A resist pattern was formed by drawing and developing.

  Next, the concavo-convex pattern was formed by etching the quartz substrate by anisotropic dry etching using an ICP dry etching apparatus. The anisotropic etching conditions were as follows: CHF3 flow rate 20 sccm, CF4 flow rate 20 sccm, Ar flow rate 80 sccm, pressure 2 Pa, ICP power 300 W, and RIE power 50 W. Next, the resist was peeled off by O 2 plasma ashing (conditions: O 2 flow rate 500 sccm, pressure 30 Pa, RF power 1000 W) to manufacture a quartz mold. The mold pattern is a line & space pattern including recesses having different widths. The pattern region includes a split region having a recess width of 25 nm, a split region having a recess line width of 500 nm, and a split region having a recess width of 1000 nm. A region was formed.

  Subsequently, a release process was performed only on the surfaces of the divided regions having a line width of 25 nm and a 500 nm to form a release layer. Durasurf (registered trademark) HD-1101Z manufactured by Daikin Industries, Ltd. was used as the release material. For IJ application, an inkjet printer DMP2831 manufactured by FUJIFILM Dimatix was used. For the divided region having a line width of 25 nm, the mold release material was filled in the IJ head, discharged to the desired divided region of the quartz mold, and the pattern surface was covered with the mold release material using capillary action. Thereafter, a rinsing process was performed on a Bertrell (registered trademark) XF-UP manufactured by Mitsui DuPont Fluorochemical Co., Ltd. under conditions of an immersion speed of 15 mm / sec and a lifting speed of 5 mm / sec, and the mold release process was completed. For the divided region with a line width of 500 nm, a release material diluted with OPTOOL (registered trademark) HD-ZV to a concentration of 50% is used and processed in the same manner as when the line width is 25 nm. A mold layer was formed. The mold release process was not performed on the pattern portion having a line width of 1000 nm.

  Through the above steps, a quartz mold having a release layer only on a part of the divided regions was manufactured.

  As a result of measuring the surface energy in each divided region, it was as shown in Table 1 below. In addition, Kyowa Interface Science Co., Ltd. DM-501 was used for the measurement.

<Comparative Example 1>
A quartz mold was produced in the same manner as in Example 1 except that the dip coating was performed as a mold release treatment method. The specific immersion method is as follows. As a release material, Durasurf (registered trademark) HD-1101Z was diluted with Optool (registered trademark) HD-ZV to a concentration of 25%. The quartz mold was subjected to dip coating on the release material under the conditions of a dip speed of 15 mm / sec, a dip time of 2 hours, and a pulling speed of 5 mm / sec. Then, the rinse process was performed like Example 1. FIG.

  As a result of measuring the surface energy in each divided region, it was as shown in Table 2 below.

<Comparative example 2>
Using the IJ coating method as a mold release treatment method, Durasurf (registered trademark) HD-1101Z as a mold release material diluted to 50% concentration with OPTOOL (registered trademark) HD-ZV was applied to the entire pattern surface. A quartz mold was produced in the same manner as in Example 1 except that the release layer was formed.

  As a result of measuring the surface energy in each divided region, it was as shown in Table 3 below.

<Comparative Example 3>
A quartz mold was manufactured in the same manner as in Example 1 except that no mold release treatment was performed.

  As a result of measuring the surface energy in each divided region, it was as shown in Table 4 below.

<Evaluation method>
Using the quartz molds manufactured in each of the examples and comparative examples, the items of “resist filling” and “pattern releasability” are evaluated for each mold pattern, and comprehensively based on the evaluation results Judgment was made.

  The resist filling property was evaluated by observing the cross-sectional shape of the mold without releasing the mold with a scanning electron microscope (SEM) after curing with UV. When the resists are filled in the recesses of all the mold patterns, the resist filling property is evaluated as good (◯). For example, when there is an unfilled portion as shown in FIG. 3a, the resist filling property is evaluated as poor (×). did.

  The evaluation of pattern releasability was performed by observing the shape of the resist pattern after releasing the mold with an atomic force microscope (AFM) or SEM. When there was no defect in the resist pattern, the pattern releasability was evaluated as good (◯). For example, when the resist pattern was defective as shown in FIG. 3B, the pattern releasability was evaluated as poor (×).

  And in the overall judgment, based on the evaluation of the above two items, when all items of “resist filling property” and “pattern releasability” are good (◯) in all pattern sizes (divided regions) In general, it was judged as being good (O), and in other cases, it was judged as being overall poor (X).

<Result>
Table 5 below shows the individual evaluation results for the examples and comparative examples, and the results of comprehensive judgment based on them. When nanoimprinting was performed using the mold manufactured in the example, there was no defect in all the divided regions having a line width of 25 nm, 500 nm, and 1000 nm, and the shape was accurately reversed, and good results were obtained.

  On the other hand, when nanoimprinting was performed using the mold manufactured in Comparative Example 1, the shape of the resist pattern in the divided region having a line width of 25 nm was favorable because the mold pattern was inverted. However, in the divided regions related to 500 nm and 1000 nm, there was a part where the resist was not filled in the mold pattern.

  When nanoimprinting was performed using the mold manufactured in Comparative Example 2, the pattern shape of the divided region having a line width of 500 nm was favorable because the mold pattern was inverted. However, a part of the resist pattern was missing in the divided region having a line width of 25 nm. In addition, in the divided region relating to the line width of 1000 nm, there was a portion where the resist was not filled in the mold pattern.

  When nanoimprinting was performed using the mold manufactured in Comparative Example 3, the pattern shape of the divided region having a line width of 1000 nm was favorable because the mold pattern was inverted. However, a part of the resist pattern was missing in the divided region having a line width of 25 nm or a line width of 500 nm.

  As a result, it was proved that the use of the mold of the present invention reduces the occurrence of resist pattern defects even when a plurality of pattern sizes exist in one mold pattern.

  The mold for imprinting of the present invention is not limited to a specific imprinting method, and requires a thermal imprinting method for pattern transfer to a thermoplastic resin, a photoimprinting method for pattern transfer to a photocurable resin, and heat and light. It can also be applied to room temperature imprint methods that transfer patterns to HSQ (Hydrogen Silses Quioxane), sol-gel imprint methods that transfer patterns to gel-like glass materials, and direct imprint methods that transfer patterns directly to metal or glass. .

DESCRIPTION OF SYMBOLS 1 Mold 2, 3 Release material 4 Board | substrate 5 Resist 6 Bubble 10 Mold main body R Pattern area | region R1, R2, R3 Division | segmentation area | region

Claims (12)

In the mold for nano-imprint in which a fine uneven pattern including a plurality of recesses having different widths is formed on the surface,
With respect to the divided region that is a divided region of the pattern region in which the uneven pattern is formed and is divided according to a predetermined division with respect to the width of the concave portion, the divided region belonging to the larger width portion has a higher surface energy in the concave portion. A mold characterized by that. The surface energy in the divided region belonging to the section where the width of the recess is less than 250 nm is less than 20 mJ / mm ² ;
The surface energy of the divided regions where the width of the recess in segments less than 750nm or 250nm is less than 20 mJ / mm ² or more 40 mJ / mm ^2,
The mold according to claim 1, wherein the surface energy in the divided region belonging to the section in which the width of the concave portion is 750 nm or more is 40 mJ / mm ² or more. The mold according to claim 2, wherein the surface energy in the divided region belonging to the section in which the width of the recess is less than 50 nm is less than 15 mJ / mm ² . The mold according to claim 2 or 3, wherein the surface energy in the divided region belonging to the section where the width of the concave portion is 1000 nm or more is 70 mJ / mm ² or more.   The mold according to any one of claims 1 to 4, wherein a release layer corresponding to a section to which the divided area belongs is provided for each of the divided areas in at least a part of the pattern area. In a method for producing a mold for nanoimprinting,
Prepare a mold body with a fine concavo-convex pattern that includes a plurality of recesses with different widths on the surface,
With respect to the divided area of the pattern area where the uneven pattern is formed and divided according to a predetermined section with respect to the width of the recess, the divided area belonging to the section with a larger width has a higher surface energy in the recess. As described above, a method for manufacturing a mold is characterized in that surface treatment is performed on at least a part of the pattern region with the processing content corresponding to the division to which the divided region belongs for each divided region. In the divided region belonging to the section where the surface treatment has the surface energy in the divided region belonging to the section where the width of the concave portion is less than 250 nm less than 20 mJ / mm ² and the width of the concave portion is not less than 250 nm and less than 750 nm. and wherein the surface energy and 20 mJ / mm ² or more 40 mJ / mm less than ^2, the width of the recess in which the said surface energy in the divided regions included in each segment is 750nm or more 40 mJ / mm ² or more The manufacturing method of the mold of Claim 6. The method for producing a mold according to claim 7, wherein the surface treatment is performed so that the surface energy in the divided region belonging to the section in which the width of the concave portion is less than 50 nm is less than 15 mJ / mm ^2. . 9. The mold according to claim 7, wherein the surface treatment is performed so that the surface energy in the divided region belonging to the section in which the width of the concave portion is 1000 nm or more is 70 mJ / mm ² or more. Production method.   The mold according to any one of claims 6 to 9, wherein the processing content is that a release material is applied by an ink jet method while changing a release processing condition according to a division to which the divided region belongs. Manufacturing method.   A nanoimprint mold according to any one of claims 1 to 5, wherein the resist film applied on a substrate is pressed, the resist film is cured, and then the mold is peeled from the resist film. Nanoimprint method.   A method for producing a patterned substrate, comprising: forming a resist film having a concavo-convex pattern transferred thereon on a substrate to be processed by the nanoimprint method according to claim 11; and etching the resist film as a mask.