WO2011122605A1

WO2011122605A1 - Mold having release layer for imprinting, method for producing mold having release layer for imprinting, and method for producing copy mold

Info

Publication number: WO2011122605A1
Application number: PCT/JP2011/057762
Authority: WO
Inventors: 宏太鈴木; 英雄小林
Original assignee: Hoya株式会社
Priority date: 2010-03-30
Filing date: 2011-03-29
Publication date: 2011-10-06

Abstract

Provided is a mold having a release layer, in which the release layer is disposed in the mold which transfers a specific uneven pattern onto a molding material to be patterned by means of the imprinting method, wherein the main chain of the molecular chains of a compound contained in the release layer contains fluorocarbons, the molecular chains of the compound have at least two adsorption functional groups that are adsorbed or bonded to the mold, the bonding energy in the adsorption functional groups that becomes the source of adsorption or bonding of the adsorption functional groups to the mold is greater than the bonding energy between one adsorption functional group and another adsorption functional group in the molecular chains of the compound, and the surface free energy of the release layer is optimized by means of heating.

Description

Mold with release layer for imprint, method for manufacturing mold with release layer for imprint, method for manufacturing copy mold

The present invention relates to a mold with a release layer for imprint, a method for producing a mold with a release layer for imprint, and a method for producing a copy mold.

2. Description of the Related Art Conventionally, in magnetic media used in hard disks and the like, a method has been used in which magnetic particles are miniaturized, the magnetic head width is minimized, and data tracks on which information is recorded are narrowed to increase the density.

On the other hand, the density of this magnetic medium is increasing, and the magnetic influence between adjacent recording tracks or recording bits cannot be ignored. For this reason, the conventional method has a limit in increasing the density.

In recent years, magnetic media called patterned media have been proposed. With patterned media, adjacent recording tracks or recording bits are magnetically separated by a card band made of grooves or non-magnetic material, reducing magnetic interference and improving signal quality, achieving higher recording density It is something to try.

As a technique for mass-producing this patterned media, the fine unevenness of a master mold (also called a master) or a copy mold (also called a working replica) that is duplicated by transferring the master mold one or more times as the original mold There is known an imprint technique (or nanoimprint technique) for producing a patterned medium by transferring a pattern (also referred to as a pattern) to a transfer substrate (here, a magnetic medium). The imprint technique is a technique in which a pattern formed on a master mold is transferred once or a plurality of times to a transfer object, and is replicated on a final transfer object (product) for mass production.

Here, various techniques are known for preparing a master mold. Among them, a technique is known in which the substrate itself is etched so as to have a predetermined pattern, and this substrate itself is used as a mold (see, for example, Patent Document 1).

In the imprint mold mentioned here, generally, the master mold itself provided with a fine pattern is not used. Instead, the master mold (primary mold) pattern is transferred to another transferred substrate, and a secondary mold is formed and copied, or the secondary mold pattern is further transferred to another transferred substrate. A tertiary mold that has been transferred to a pattern and copied to form a pattern, or a copy mold that has been copied to a higher order is used.
Even if these copy molds are deformed, broken, or contaminated, if the master mold is safe, a copy mold can be produced from the master mold again.

For example, in order to actually produce the above-mentioned patterned media in large quantities, a plurality of imprint apparatuses are arranged and operated in parallel. Therefore, it is necessary to prepare and prepare a plurality of copy molds on which a predetermined identical fine pattern is formed for the plurality of imprint apparatuses. In order to produce a plurality of copy molds, as described above, a master mold (or a copy mold to be an original mold, hereinafter referred to simply as a mold) on which a pattern is formed is placed on a transferred substrate. It is necessary to transfer the pattern by pressing against the pattern forming material (resist layer or simply referred to as resist), and then release the mold from the resist layer, that is, the substrate to be transferred. Furthermore, it is necessary to repeat the above steps continuously to produce a large number of copy molds (working replicas).

Here, in order to release the mold smoothly from the resist layer, that is, from the substrate to be transferred, a release agent compound is applied to the mold surface in advance to form a release layer, and then release properties are applied. It is known to perform pattern transfer.

By providing the mold with a release layer, it is possible to improve the release property between the release layer and the resist layer while having sufficient adhesion between the mold and the release layer. The release from the resist layer, that is, the transfer substrate can be performed smoothly and at a low release pressure. As a result, it is possible to reduce the damage to the mold, the damage (defect) of the transferred pattern, or the damage to the mold and the imprint apparatus due to the mold release failure or failure.

As a release agent compound, for example, Patent Document 2 describes a technique using a surface modifier composed of an organic silicone compound having a linear perfluoropolyether structure.

Patent Document 3 describes a silicone-based release agent compound having an organopolysiloxane structure as a basic structure. Specifically, polysiloxane containing unmodified or modified silicone oil and trimethylsiloxysilicic acid. And silicone acrylic resins.

JP 2008-310944 A Special table 2008-537557 JP 2010-006870 A

As described in

Patent Documents

2 and 3, perfluoropolyether compounds and silicone compounds are generally used as release agent compounds for nanoimprinting.

In these release agent compounds, generally, only one terminal group of the molecular chain of the release agent compound is a functional group for chemically bonding to the mold surface on which the release layer is to be provided. In addition, a modified silane group is often used as this functional group, and these undergo dehydration condensation due to silanol bonds on the mold surface. The molecular chain of the release agent compound is adsorbed on the mold surface.

On the other hand, in the release agent compound, the portion where the modified silane group is not provided, that is, the portion of perfluoroether group or silicone reduces the surface free energy on the surface of the release layer contacting the pattern forming material. . As a result, the mold can be released from the pattern forming material, that is, the transferred substrate, smoothly and with a low release pressure.

Here, in a release agent compound in which a modified silane group is provided at one end as in

Patent Documents

2 and 3, the modified silane group at the end of the molecular chain is in close contact with the substrate and has a strong adhesion. A mold layer can be formed.

However, on the other hand, the modified silane group at the end of the release agent compound is highly reactive and easily reacts with water in the atmosphere other than the mold surface. As a result, agglomeration due to the release agent compound itself may occur. When such release agent compound agglomerates, the agglomerated portions become protrusions or raised defects having a considerable physical height and width as compared to the surrounding non-aggregated portions. As a result, when performing imprinting, it is difficult to smoothly and repeatedly release the mold and the pattern forming material, that is, the substrate to be transferred, that is, stably transfer the pattern. There is a risk of affecting the quality of the final transferred object (final product).

As described above, in a release agent compound in which a modified silane group is provided at one end as in

Patent Documents

2 and 3, for example, the modified silane group at the end of the molecular chain is adsorbed or bonded to the mold. Further, as shown in FIG. 11 (a), the modified silane group is provided only at one end of the molecular chain, and therefore, from the modified silane group to the other end of the molecular chain, that is, the entire molecular chain is a release layer. This is considered to be oriented in the thickness direction. In that case, the thickness of the release layer depends on the total length of the molecular chain, and when the pattern on the mold having the same size as the total length of the molecular chain is transferred and formed, the dimension of the pattern transferred to the resist layer And it can be expected to adversely affect the accuracy of the shape. Specifically, as shown in FIG. 11 (b), when the size of the predetermined pattern and the length of the molecular chain of the release agent compound are about the same, the separation having a thickness about the size of the pattern. In the mold layer, there is a possibility that a predetermined pattern size and shape to be transferred to the resist layer may be greatly changed, and the pattern transfer accuracy may be deteriorated.

Furthermore, in the release agent compound, as described above, the perfluoroether group and the silicone portion reduce the surface free energy of the release layer that is in direct contact with the resist layer. As a result, the mold and the resist layer, that is, the transfer substrate, can be released smoothly and with a low release pressure. Therefore, in order to obtain a good release capability, it is considered preferable to reduce the surface free energy of the release layer surface in contact with the pattern forming material as much as possible.

However, if the surface free energy of the release layer that is in direct contact with the material to be patterned is reduced, there may be a problem that the resist is not satisfactorily filled in the recesses of the uneven pattern on the mold. FIG. 10B according to the comparative example to be performed).

If the pattern forming material is not satisfactorily filled into the concave portions of the fine concavo-convex pattern of the mold, the predetermined pattern size and shape are not accurately transferred in the portion, which results in a transfer defect. As a result, the quality of the final transfer target (product) may be affected.

The object of the present invention has been made in consideration of the above-mentioned circumstances, and satisfactorily fills the pattern forming material into the pattern recesses on the mold while providing sufficiently high releasability. An object of the present invention is to provide a mold with a release layer for imprinting that realizes high pattern transfer, and a method for manufacturing the same. Moreover, it is providing the manufacturing method of a copy mold using the said mold with the mold release agent for imprints.

According to a first aspect of the present invention, in the mold with a release layer, a release layer is provided in a mold for transferring a predetermined concavo-convex pattern to a pattern forming material by an imprint method. The main chain of the release agent compound (molecule) contains a fluorocarbon, and the release agent compound has at least two adsorption functional groups adsorbed or bonded to the mold. In the adsorption functional group, The mold with a release layer is characterized in that the bond energy between the adsorption functional group and the mold is larger than the bond energy between the adsorption functional groups in the molecular chain of the release agent compound.
According to a second aspect of the present invention, in the invention according to the first aspect, the adsorption functional group is a functional group capable of hydrogen bonding to the mold.
According to a third aspect of the present invention, in the invention according to the first or second aspect, the adsorptive functional group is a hydroxyl group, a carboxyl group, an ester group, or any combination thereof. It is characterized by.
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the adsorptive functional groups are provided at both ends of the molecular chain of the release agent compound constituting the release layer. It is characterized by that.
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the molecular chain of the release agent compound constituting the release layer has no side chain. And
According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, the fluorocarbon includes (C _m F _2m O) _n [m is an integer and 1 ≦ m ≦ 7, n is the _(C _m F 2m _O) to integers molecular weight of _n is 500 or more and 6000 or less] are included one or a plurality of types, characterized by.
According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the release layer has a heat treatment temperature for the release layer and a surface free energy of the release layer. The relationship includes a region where the value of the surface free energy is constant even when the heat treatment temperature is changed, and a region where the value of the surface free energy increases or decreases with the level of the heat treatment temperature, and the mold release after the heat treatment The layer is characterized by having a region where the value of the surface free energy increases as the heat treatment temperature decreases.
According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the mold is made of a quartz substrate provided with a concavo-convex pattern corresponding to a predetermined pattern. To do.
The ninth aspect of the present invention provides
In a mold with a release layer in which a release layer is provided in a mold for transferring a predetermined concavo-convex pattern to a pattern forming material by an imprint method, the main chain in the molecular chain of the release agent compound constituting the release layer (C _m F _2m O) _n [m is an integer and 1 ≦ m ≦ 7, and n is an _{integer such that} the molecular weight of (C _m F _2m O) _n is 500 or more and 6000 or less]. Or a plurality of types, wherein the release agent compound has at least two hydroxyl groups as an adsorption functional group for the mold, the hydroxyl groups are provided at both ends of the release agent compound, and the release layer In the relationship between the heat treatment temperature for the release layer and the surface free energy of the release layer, the surface free energy value is substantially constant even when the heat treatment temperature is changed. A region in which the value of the surface free energy increases or decreases with the level of the heat treatment temperature, and the release layer after the heat treatment has a region in which the value of the surface free energy increases with a decrease in the heat treatment temperature. It is the mold with a release layer characterized.
A tenth aspect of the present invention is a method for manufacturing a mold with a release layer according to the first aspect, wherein a release agent compound is applied to the mold, and then the release layer is heated by heat treatment. It is a method for producing a mold with a release layer, characterized by having a step of optimizing the surface energy of the release layer by changing the surface free energy.
An eleventh aspect of the present invention is characterized in that, in the invention described in the tenth aspect, the method includes a step of performing a heat treatment at 25 ° C. or more and 250 ° C. or less.
According to a twelfth aspect of the present invention, in the invention according to the tenth or eleventh aspect, the method includes a step of rinsing the release layer after the heat treatment.
A thirteenth aspect of the present invention is a method for producing a copy mold from the mold with a release layer according to the first aspect, the step of providing a release layer on the mold, and the production of the copy mold A step of forming a hard mask layer on the substrate, a step of forming a resist layer on the hard mask layer, a step of transferring a pattern of the mold to the resist layer, and a pattern of the mold. Etching the hard mask layer using the transferred resist layer as a mask, etching the substrate for manufacturing the copy mold using the hard mask layer etched using the resist layer as a mask, and It is a manufacturing method of the copy mold characterized by having.

According to the present invention, the pattern forming material on the mold is satisfactorily filled with a satisfactory mold release property, with a lower mold release pressure, without hindrance, and the pattern is formed stably and continuously with high accuracy. Can be transferred.

It is a conceptual diagram for demonstrating a mode that the adsorption | suction functional group in the molecular chain of the mold release agent compound concerning this embodiment adsorb | sucks or couple | bonds with the mold surface. (A) is when the hydroxyl group is at the end of the molecular chain, (b) is when the hydroxyl group is other than at the end of the molecular chain, (c) is a state in which van der Waals force is acting on the main chain, (d ) Shows the situation when there are 3 hydroxyl groups, and (e) shows the situation when there are 4 hydroxyl groups. It is a section schematic diagram for explaining a mold with a release layer concerning this embodiment. It is a cross-sectional schematic diagram for demonstrating the process of manufacturing a copy mold using the mold with a release layer of FIG. It is a conceptual diagram for demonstrating the mode of the molecular chain at the time of heat-processing the mold with a release layer which concerns on this embodiment. It is a figure which shows the result of having measured the surface roughness using the atomic force microscope about the mold with a release layer obtained by the Example and the comparative example. (A) And (b) is an Example, (c) And (d) is a bird's-eye view which shows the surface roughness of the mold with a release layer in a comparative example. It is a graph which shows the result of having investigated the thickness of the mold release layer, and the imprint frequency about the mold with a mold release layer obtained by the Example and the comparative example. It is a graph which shows the result of having investigated the relationship between the surface free energy of a mold release layer, and the number of imprints about the mold with a mold release layer obtained by the Example and the comparative example. It is a graph which shows the thickness of the mold release layer for imprints about the mold with the mold release layer for imprints obtained by the Example and the comparative example. It is a graph which shows the relationship between the heat processing temperature and surface free energy in an Example and a comparative example. (A) is an Example and (b) is a graph which concerns on a comparative example. It is the photograph which showed a mode that the resist was filled in the pattern on a mold, when the mold with the mold release layer for imprint which concerns on this embodiment was pressed against the resist layer on a to-be-transferred substrate. (A) is an Example, (b) is a photograph according to a comparative example. In a comparative example, (a) is a conceptual diagram for explaining how the pattern size is changed by providing a release layer, and (b) is a mold in the case where a silane group exists only at one end of a molecular chain. It is a conceptual diagram for demonstrating the mode of adsorption | suction or coupling | bonding with a mold release layer.

The present inventors have studied various release layers that have imprint resistance but can suppress the occurrence of defects due to self-aggregation. In this study, the present inventors found that the modified silane group of the conventional silicone release agent contributes to the adhesiveness (that is, adsorption or bonding) between the mold and the release layer, and at the same time, self-aggregation. We paid attention to that it contributed to

The inventors of the present invention have the following relationship between the modified silane group (that is, the functional group adsorbed to the mold) and the binding energy between the mold and the adsorbed functional group during self-aggregation. Pay attention. As a result, if the bond that causes the adsorption of the mold and the adsorption functional group is more stable than the bond between the adsorption functional groups at the time of self-aggregation, mold release becomes a problem during imprinting. It has been found that self-aggregation of the agent compound can be suppressed.

Furthermore, the present inventors paid attention to the fact that the conventional modified silane group as shown in FIG. 11B is provided only at one end of the release agent compound that forms the release layer for imprint. . And by having a plurality of the above-mentioned adsorptive functional groups, as shown in FIG. 1, the dimensional accuracy of the transfer pattern can be improved so that the thickness of the release layer is not controlled by the total length of the molecular chain of the release layer. I found.

Furthermore, the present inventors formed a good pattern on the resist layer, contrary to the conventional release agent compound that the surface free energy of the release layer on the mold should be reduced as much as possible. In order to achieve this, it has been found that it is necessary to perform optimization mainly to increase the surface free energy appropriately.

Specifically, the surface free energy of the release layer is intentionally changed by intentionally changing the surface free energy of the release layer in the part that is in direct contact with the resist layer by raising or lowering the temperature of the heat treatment after application of the release agent compound. It was found that the resist could be satisfactorily filled into the recesses of the concavo-convex pattern on the mold through the release layer for imprinting (see FIG. 10 (a) according to an example described later)).

<Embodiment 1>
Hereinafter, embodiments of the present invention will be described.
As an order, first, the process of providing the release layer on the mold will be described with reference to FIG. 2 which is a schematic sectional view. Then, the process of manufacturing the copy mold 20 from the master mold which is the master disk by the optical nanoimprint technique will be described with reference to FIG. 3 which is a schematic sectional view.

Here, when pattern transfer is performed using the above-described copy mold, a release layer may naturally be provided in the copy mold. In this embodiment, the mold includes a master mold for imprinting, a primary copy mold transferred from the master mold, and a secondary copy mold, a secondary copy mold, a tertiary copy mold, and the like.

(Preparation of mold)
First, as shown in FIG. 2, a mold 30 is prepared, which is an original pattern of the uneven pattern transferred to the copy mold 20.
The mold 30 may be made of any material as long as it can be used as an imprint mold, but has a light-transmitting property with respect to exposure light used in the optical nanoimprint method (for example, exposure light is ultraviolet light). In this case, it is preferable to use quartz or the like, since the irradiation of the later-described exposure can be performed from the back surface of the mold 30 (that is, the side where the pattern is not formed). If the substrate 1 for copy mold manufacture has translucency, exposure can also be performed from the substrate side for copy mold manufacture (that is, the back surface side where pattern transfer is not formed). In this case, the mold 30 may be made of a material that is opaque to the exposure light (for example, a silicon wafer when the exposure light is ultraviolet light).
In addition, the mold release layer 31 is not provided directly on the substrate, but the mold release layer 31 is provided on the layer of the other functional material with respect to the mold 30 provided with a layer made of another functional material on the substrate. It may be provided.
In the present embodiment, a case where a substrate made of quartz (also referred to as a quartz substrate) on which unevenness corresponding to a predetermined uneven pattern is formed is used for the mold 30 will be described.

Note that the predetermined concavo-convex pattern provided on the quartz substrate may be on the micron order, but in the present embodiment, it is targeted on the nano order (for example, a groove pattern having a width of about 10 nm).

In addition, when a predetermined uneven pattern provided on the mold 30 is transferred by the imprint method, an uneven pattern opposite to the predetermined uneven pattern is formed on the copy mold. Therefore, if the concave / convex pattern of the copy mold is a pattern to be finally obtained, a pattern having concave and convex portions opposite to the concave / convex pattern is formed on the mold 30. In addition, after transferring the concave / convex pattern to the primary copy mold, the concave / convex pattern of the primary copy mold is transferred once again to produce a secondary copy mold. May be obtained.

(Installation of release layer on mold)
And in this embodiment, as shown in FIG. 2, the mold release layer 31 is formed by apply | coating the mold release agent compound to the part in which at least the predetermined uneven | corrugated pattern of this mold 30 was formed.
By providing the release layer 31, the resist layer 4 provided on the copy mold manufacturing substrate 1 shown in FIG. 3 to be described later and the mold 30 (directly the release layer 31) are brought into contact with each other. After filling the concavo-convex pattern with the resist 4 and then curing the resist 4 by exposure, the mold 30 can be easily separated (released) from the resist layer 4 with a smooth and low release pressure.
As a result, damage to the mold 30, damage to the transferred pattern (defect) due to defective release or failure, or damage to the mold and the imprint apparatus can be reduced.

Hereinafter, the release layer 31 will be described in detail.
(Outline of structure of release agent compound)
In the present embodiment, the compound constituting the release layer is referred to as “release agent compound” or simply “compound”. Hereinafter, the structure of the release agent compound in the present invention will be described in detail.
First, the release agent compound constituting the release layer 31 according to this embodiment includes a main chain portion that contributes to release and an adsorption functional group for adsorbing or binding to the mold 30.

(Main chain part of release agent compound)
The main chain in the molecular chain of the release agent compound contains a fluorocarbon. The surface free energy of the release layer 31 that is in direct contact with the resist layer 4 provided on the substrate 1 for producing a copy mold is reduced by fluorine in the fluorocarbon. As a result, release can be performed smoothly and with a low release pressure.

Incidentally, the fluorocarbon preferably includes one kind or more kinds _{_{_{(C m F 2m O) n}}} . Thus, by including a perfluoroether group in the main chain of the release agent compound, as shown in FIG. 1, the whole molecular chain becomes a random coil shape, and the flexibility of the molecular chain can be improved. In a release agent compound that does not contain an ether group that has been generally used, the thickness of the release layer depends on the total length of the molecular chain due to the orientation of the molecular chain in the mold thickness direction. In the release agent compound used in the invention, the flexibility of the molecular chain is improved, and the degree of orientation of the molecular chain in the thickness direction of the release layer 31 is relaxed. As a result, the thickness of the release layer 31 is reduced as compared with the conventional case.

The value of m is preferably an integer and 1 ≦ m ≦ 7.
If m is 1 or more, the flexibility is exhibited moderately, the distance between the molecular chains after adsorbing to the mold 30 can be appropriately close, and the molecular chains composed of moderately dense fluorocarbons, The surface free energy of the release layer 31 can be sufficiently reduced.
If m is 7 or less, the rigidity is moderately exhibited, so that the layer thickness can be prevented from depending on the total length of the molecular chain. In order to balance such adhesion and rigidity of molecular chains, it is particularly preferable that m is 3 or 4.

The value of _n is preferably an integer such that the molecular weight of (C _m F _2m O) _n is 500 or more and 6000 or less.
(C _m F _2m O) _If the molecular weight of _n is 500 or more, the functional chains of the releasing agent compound are not easily aggregated due to the short molecular chain of the release agent compound. Further, the intermolecular force in the direction in which the molecular chains after adsorbing or bonding to the surface of the mold 30 are brought close to each other can be maintained, and the surface free energy of the release layer 31 is obtained by the molecular chains composed of moderately dense fluorocarbons. Can be sufficiently reduced.
In addition, when the molecular weight is 6000 or less, the effect of reducing the layer thickness of the release layer 31 is not offset by the molecular chain being too long.
As a specific value of n, 6 or 7 is preferable.

In addition, (C _m F _2m O) _n may be a random copolymer in a plurality of types or a block copolymer. An example is a random copolymer of (CF ₂ O) and (C ₂ F ₄ O).

(Adsorption functional group of release agent compound)
The release agent compound constituting the release layer 31 has at least two adsorption functional groups for the mold 30.
As described above, the release layer 31 is required to release the resist layer 4 provided on the copy mold substrate and the mold smoothly and with a low release pressure. At the same time, the mold release layer 31 can maintain the imprint durability when repeating physical contact and mold release with the resist layer 4, that is, the surface free energy value of the mold release layer and the thickness of the mold release layer. Desired. Specifically, the release layer 31 needs to have sufficient adhesion to the mold 30. If the adhesive layer does not have sufficient adhesion, the release layer 31 is peeled off from the mold during imprinting and transferred to the surface of the resist layer 4, and the above-described imprint durability is deteriorated. In addition, a transfer defect may occur, which may affect the pattern accuracy and quality of the copy mold.
In this embodiment, by providing a plurality of adsorption functional groups for the mold, two or more adsorption functional groups can be used for one molecular chain in the release agent compound even if the mold 30 and one adsorption functional group cannot be firmly adsorbed. If a group is provided, adsorption points for the mold 30 can be provided at two or more locations of one molecular chain, and as a result, adhesion between the mold 30 and the release layer 31 can be enhanced.

In order to improve the adhesion between the mold 30 and the release layer 31, the adsorptive functional groups are portions close to both ends of the molecular chain of the release agent compound constituting the release layer 31 (FIG. 1 ( b)), more preferably provided at both ends (FIG. 1 (a)). If the adsorptive functional group is at both ends of the molecular chain or at a portion close to both ends, the molecular chain of the release agent compound can be prevented from being oriented substantially linearly in the thickness direction of the release layer, As a result, the thickness of the release layer can be greatly reduced as compared with the conventional case. In addition, the adhesiveness between the mold 30 and the release layer 31 can be improved by firmly bonding to the mold 30 at two distant locations in the molecular chain.

The following effects can also be expected when the adsorptive functional groups are present in portions close to both ends in the molecular chain of the release agent compound constituting the release layer 31. That is, when the adsorptive functional group is adsorbed on the mold 30, it is presumed that the main chain becomes a random coil shape as described above. However, as shown in FIG. 1C, an interaction such as van der Waals force acts between the main chain and the mold 30, and a physical force in the direction toward the mold 30 is applied to the main chain. Inferred to work.

Furthermore, when the adsorption functional group is provided in the portion close to both ends of the molecular chain as described above, as shown in FIG. 1 (d), the adsorption functional group is further added to the central portion of the molecular chain rather than that portion. It is preferable to have. By doing so, the adsorption point or bonding point on the mold surface in the molecular chain of the release agent compound can be increased, and as a result, the thickness of the release layer can be further reduced. In particular, from the balance between improved adhesion, improved releasability, and suppression of self-aggregation, as shown in FIGS. 1 (d) and 1 (e), the release agent compound has a total of the adsorbing functional groups. And preferably 3 or 4.

(Binding energy of adsorption functional group)
In the present invention, the release agent compound includes a release agent compound in which the binding energy that causes the adsorption between the adsorptive functional group and the mold is greater than the binding energy of the adsorptive functional groups in the molecular chain of the release agent compound. Select. As described above, in the imprint method, self-aggregation of the release agent compound is one of the factors that deteriorate the accuracy or quality of the transfer pattern. However, by using a compound having such a binding energy relationship as a release agent compound, even if the adsorptive functional group causes self-aggregation, the surface of the mold 30 (substance naturally present on the surface ( Self-aggregation is released because the binding energy between the adsorbing functional group and the adsorbing functional group is higher. Finally, the surface of the mold 30 and the adsorption functional group are adsorbed or bonded. As a result, by suppressing the self-aggregation of the release agent compound and the occurrence of defects accompanying therewith, it is possible to suppress a decrease in accuracy or quality of the transfer pattern.

The adsorbing functional group is preferably a hydroxyl group, a carboxyl group, an ester group, or any combination thereof. This is because the functional group is less likely to cause self-aggregation than the modified silane group. Even if the adhesion (bonding force) of one adsorbing functional group to the mold 30 is lower than that of the modified silane group, as described above, in this embodiment, two adsorbing functional groups are added to one molecular chain. More than one are provided, and sufficient adhesion to the mold 30 can be ensured. In view of the binding energy, that is, improvement of adhesion and suppression of self-aggregation, the adsorptive functional group is preferably a hydroxyl group.

In addition, although it demonstrated that the said adsorption functional group adsorb | sucks or couple | bonds with the mold 30, when the said adsorption functional group consists of a hydroxyl group, a carboxyl group, an ester group, or any combination of these, it exists on the mold 30 It is considered that the water and the adsorbing functional group undergo dehydration condensation to form a strong bond. When the mold 30 is a quartz substrate, oxygen on the surface of the quartz substrate and the adsorption functional group cause hydrogen bonding, and as a result, the adhesion between the mold 30 and the release layer 31 is further improved.

(Additive)
In addition, the mold release layer comprised with this mold release agent compound may contain the well-known substance which can be added to a mold release agent other than the above compounds.

(Application of release agent to mold)
Next, a release agent compound as described above is applied onto the mold 30 in order to form and provide the release layer 31 on the mold 30. Examples of this coating method include a dipping method, a spin coating method, an ink jet method, and a spray method.

When using the dip method, the immersion time is preferably 5 minutes or longer. Within this time range, the mold release agent compound can be sufficiently uniformly applied to the mold 30. A sufficient time can be secured for the adsorptive functional group to adsorb to the mold 30.
Further, the pulling speed after immersion is preferably 80 to 200 mm / min. If the speed is less than or equal to the upper limit, the uniformity during the application of the release agent compound is not impaired by the fluctuation of the liquid level. Moreover, if the speed is equal to or higher than the lower limit, it is possible to suppress a situation in which the amount of the drawn liquid is reduced due to the meniscus force.

(Heat treatment after application of release agent compound)
For example, after applying the release agent compound to the mold 30 as described above, the mold 30 is heat-treated at 25 ° C. to 250 ° C. This is because the release layer 31 is densified by removing the solvent contained in the release agent compound (solution) and the adhesion between the mold 30 and the release layer 31 is improved. Within this temperature range, the release layer can be densified and adhesion can be improved without thermal decomposition of the release agent compound. Furthermore, by performing the heat treatment in the above temperature range, it is possible to easily adsorb or bond two or more adsorption functional groups to the mold 30 as shown in FIG. And the adhesiveness between the mold 30 and the mold release layer 31 can further be improved, and it can prevent that the thickness of a mold release layer depends on the full length of the molecular chain of a mold release agent compound.
Specific examples of the heat treatment means include a clean oven and a hot plate.

(Optimization of surface free energy by heat treatment)
When the adsorptive functional group of the present embodiment is a hydroxyl group, in the relationship between the heat treatment temperature for the release agent compound and the surface free energy of the release layer in the present embodiment (FIG. 9A), the heat treatment temperature There is a region where the value of the surface free energy is constant even if the value of the surface temperature changes, and a region where the value of the surface free energy increases as the heat treatment temperature changes (specifically, as the heat treatment temperature decreases). included. When the surface free energy of the release layer that is in direct contact with the resist layer is lowered, there may be a problem that the resist 4 is not satisfactorily filled in the recesses of the uneven pattern on the mold. On the other hand, in the present embodiment, the surface free energy of the release layer 31 is set to the composition of the resist 4 so that the fine concavo-convex pattern on the mold 30 is easily and reliably filled with the heat treatment. Can be optimized according to

In other words, a release layer whose surface free energy changes substantially by heat treatment or the like can satisfactorily and reliably fill a fine uneven pattern on the mold 30 regardless of the composition of the resist 4. be able to. Furthermore, there is a possibility that even the filling speed of the resist 4 into the pattern on the mold 30 can be adjusted.

As described above, when the surface free energy is appropriately increased by the heat treatment, the release layer 31 after the heat treatment has a desired surface free energy in a region where the value of the surface free energy increases as the heat treatment temperature decreases. Is preferably set by adjusting and optimizing the heat treatment temperature. Specifically, it is preferable to perform heat treatment at 25 ° C. or more and 170 ° C. or less with respect to the mold 30 coated with the release agent compound.

ならば Within this temperature range, the surface free energy that has decreased too much can be increased appropriately by lowering the heat treatment temperature from 170 ° C. Then, according to the composition of the resist 4 to be used, the resist 4 is reliably, satisfactorily and quickly filled into the fine concavo-convex pattern on the mold 30 through the release layer 31 without impairing the release property. can do.

In addition, within this temperature range, the solvent of the release agent compound (solution) remaining in the release layer can be removed, the release layer 31 is further densified, and the mold 30 and the release layer 31 It is possible to improve the adhesion. Moreover, if it is this temperature range, the film thickness of a mold release layer can be maintained, without generating the thermal decomposition of a mold release agent compound, ie, a favorable mold release property can be maintained.

(Rinse treatment)
After performing the heat treatment as described above, a rinse treatment is performed on the mold 30 on which the release layer 31 is formed. This rinsing process is performed to wash away and remove the excess release agent compound that has not been adsorbed or bonded to the surface of the mold 30.

In the present embodiment, it is meaningful to perform the rinsing process after performing the heat treatment as described above. This is because if the rinse treatment is performed without performing the above-described heat treatment, the release agent compound that is not sufficiently adsorbed or bonded to the mold 30 is also washed away from the mold 30. However, after the above heat treatment, the release agent compound can be adsorbed or bonded to the surface of the mold 30 as much as possible. In other words, the heat treatment (or depending on the temperature) promotes the adsorption or binding of the release agent compound to the mold. Therefore, by performing the rinse treatment after the heat treatment, it is possible to wash away only the excess release agent compound that is not adsorbed or bonded to the mold 30. As a result, it is possible to suppress an increase in surface energy due to an excessive release agent compound, and it is not necessary to reduce the release property and to increase the thickness of the release layer. Further, the reduction of the release layer thickness according to the number of imprints, the fluctuation of the surface free energy, and the like are suppressed, and the imprint resistance of the release layer 31 is stabilized. Any rinse liquid may be used as long as it does not dissolve the heat-released release layer 31.

The above is the step of forming the release layer 31 on the mold 30.
Hereinafter, a process for producing a copy mold by the optical imprint method using the mold 30 with the release layer 31 will be described with reference to FIG.

(Preparation of copy mold manufacturing substrate)
First, as shown in FIG. 3A, the substrate 1 for the copy mold 20 is prepared.
The substrate 1 may be any material that can be used as the copy mold 20, and examples thereof include quartz, sapphire, and a silicon wafer. In addition, if the use of the copy mold is the optical nanoimprint method, a quartz substrate having translucency with respect to the exposure light used in the optical nanoimprint method may be used.

Further, as for the shape of the substrate 1, it may be a disc shape (wafer shape), or may be a rectangle, a polygon, or a semicircle.
In the present embodiment, a quartz wafer having the same shape as the mold 30 will be described as the substrate 1 in order to manufacture the copy mold 20.

(Formation of hard mask layer)
Next, as shown in FIG. 3B, the substrate 1 that has been appropriately polished and cleaned is introduced into a sputtering apparatus. In this embodiment, a target made of an alloy of tantalum (Ta) and hafnium (Hf) is sputtered with argon gas to form the conductive layer 2 made of tantalum-hafnium alloy, and the hard mask layer 7 is formed on the substrate 1. A lower layer (conductive layer 2) was formed.

Note that the material of the conductive layer 2 may be one used as a known conductive layer. As an example, a film composition containing Ta as a main component can be mentioned. In this case, TaHf, TaZr, TaHfZr, etc. are suitable. In the present embodiment, the conductive layer 2 made of tantalum-hafnium (TaHf) will be described.

Next, in the present embodiment, from the viewpoint of preventing oxidation of the conductive layer 2, exposure to the atmosphere is not performed, and a chromium (Cr) target is continuously sputtered with a mixed gas of argon and nitrogen to form chromium nitride. Layer 3 was formed and formed as an upper layer (antioxidation layer 3 for conductive layer) in hard mask layer 7.

The material of the antioxidant layer 3 is preferably chromium nitride (CrN) from the viewpoint that it is not necessary to use oxygen in sputtering at the time of film formation, but any other composition can be used as the antioxidant layer. . For example, molybdenum, chromium oxide (CrO), SiC, amorphous carbon, or Al may be used. In the present embodiment, the antioxidant layer 3 made of chromium nitride (CrN) will be described.

Thus, as shown in FIG. 3B, a hard mask layer 7 having the tantalum-hafnium alloy layer 2 as a lower layer and the chromium nitride layer 3 as an upper layer is formed on the substrate 1.

Note that the “hard mask layer” in the present embodiment is not limited to the above combination, and includes a single layer or a plurality of layers, and a protrusion corresponding to a desired concavo-convex pattern formed in a copy mold is the substrate. As long as it can protect the portion to be formed on the substrate 1 (transfer substrate) and can serve as an etching mask for groove processing (recess formation) on the substrate 1, the material, material, composition It doesn't matter. Further, the antioxidant layer 3 in the hard mask layer 7 may also serve as the conductive layer 2. In that case, a conductive layer such as TaHf can be omitted.
Here, what provided the hard mask layer 7 on the board | substrate 1 is called copy mold production blanks in this embodiment.

(Formation of resist layer)
The copy mold manufacturing blanks are appropriately washed and subjected to a dehydration baking process, and then, as shown in FIG. 3C, a resist 4 for optical nanoimprinting is applied and formed on the hard mask layer 7. Thereafter, heat treatment may be appropriately performed as necessary. Examples of the resist 4 for photo-nanoimprint include a photo-curable resin, particularly an ultraviolet curable resin. The resist 4 can be applied to the imprinting method used and is suitable for an etching process to be performed later, that is, has sufficient etching selectivity with respect to the hard mask layer. Does not matter.

Further, the thickness of the resist layer 4 at this time is equal to or greater than the thickness at which the resist 4 remains until various etchings are completed at a portion to be a mask (that is, a portion to be a convex (projection) portion on the copy mold). It is preferable that

Note that an adhesion auxiliary layer may be provided on the hard mask layer 7 in advance before the resist layer 4 is provided. By providing the adhesion auxiliary layer, it is possible to prevent the resist layer 4 from being peeled off during the imprint process or the etching process and the pattern from being lost.

(Pattern transfer by nanoimprint method)
Next, as shown in FIG. 3D, a mold 30 on which a fine uneven pattern and a release layer 31 are formed is placed on the resist layer 4, and then the resist 4 is placed on the mold 30. Let stand until the uneven pattern is completely filled.
At this time, if the resist layer 4 is substantially liquid, the mold 30 may be placed on the resist layer 4 and allowed to stand, and it is not necessary to press strongly. When the resist layer 4 is substantially solid, the mold 30 is pressed relatively strongly against the resist layer 4 until the resist layer 4 is completely filled in the fine uneven pattern of the mold 30. Put.

After that, the resist layer 4 is cured by exposure using an ultraviolet light irradiation device while keeping the mold 30 and the resist layer 4 (that is, the quartz wafer for producing a copy mold) in close contact with each other. At this time, the irradiation with ultraviolet light is usually performed from the back surface of the mold 30 (that is, the side where the pattern is not formed). However, when the substrate 1 is translucent to the exposure light, the substrate 1 side is irradiated. You may go.

At this time, in order to prevent a transfer failure due to a positional shift between the mold 30 and the substrate 1, grooves or the like for alignment marks may be provided on both or one side of the mold 30 and the substrate to be transferred.

By the exposure, the resist 4 filled in the fine uneven pattern of the mold 30 is cured, and a fine uneven pattern is formed in the resist layer 4.

After the exposure, the mold 30 and the resist 4 are separated. As shown in FIG. 3E, the fine concavo-convex pattern which has been released and transferred to the resist 4 is exposed.

(Removal of residual film layer in resist layer)
After the fine pattern is transferred and formed on the resist layer 4, the remaining resist layer on the chromium nitride layer 3 and in the concave portions of the fine concavo-convex pattern formed on the resist layer 4 is formed by oxygen, argon, fluorine-based gas. These are removed by ashing using plasma of the mixed gas. In this way, as shown in FIG. 3F, a resist pattern corresponding to a desired fine uneven pattern is formed. A groove is formed on the substrate 1 in the concave portion of the fine concavo-convex pattern transferred and formed on the resist layer 4.

(First etching)
Next, the substrate 1 having the resist pattern formed on the surface is introduced into a dry etching apparatus. Then, first etching with a gas containing a chlorine-based gas is performed in an atmosphere substantially free of oxygen gas. At this time, it is preferable to perform etching with the reducing gas together with the reducing gas from the viewpoint of preventing oxidation of the conductive layer 2.

Note that “under an atmosphere that does not substantially contain oxygen gas” means “under an atmosphere in which the amount of inflow is such that anisotropic etching can be performed even if oxygen gas flows in during etching”. Preferably, it is an atmosphere in which the inflow amount of oxygen gas is 5% or less of the entire inflow gas.

エッチング By this etching process, as shown in FIG. 3G, a hard mask layer 7 in which a fine pattern is formed using the resist pattern as an original pattern is obtained. Note that the etching end point at this time is determined using an end point detector such as a reflection optical type.

(Second etching)
Subsequently, after the gas used in the first etching is exhausted from the etching chamber, a fine pattern is formed on the hard mask layer 7 by performing a second etching using a fluorine-based gas in the same dry etching apparatus. To the substrate 1. At this time, the substrate 1 made of quartz is etched using the hard mask layer 7 as a mask, and grooves corresponding to a fine pattern are formed on the substrate 1 as shown in FIG. Before and after that, the resist layer is removed with an alkali solution or an acid solution.

Examples of the fluorine-based gas used here include C _x F _y (for example, CF ₄ , C ₂ F ₆ , C ₃ F ₈ ), CHF ₃ , a mixed gas thereof, or a rare gas (He, Ar) as an additive gas thereto. , Xe, etc.).

Thus, as shown in FIG. 3 (h), the groove processing corresponding to the fine pattern is applied to the substrate 1 made of quartz, and the hard mask layer 7 having the fine pattern remains on the portion other than the groove of the substrate 1 made of quartz. To do. Thus, the mold 10 before removal of the remaining hard mask layer 7 is obtained.

(Removal of hard mask layer)
The hard mask layer 7 remaining on the mold 10 before removal of the remaining hard mask layer is subsequently dry-etched by the same method as the first etching for the mold 10 before removal of the remaining hard mask layer thus manufactured. The removal process is performed, and thereby an imprint mold 20 in which a fine concavo-convex pattern is formed on the surface of the substrate 1 made of quartz is manufactured (FIG. 3I).

Note that only one of the etchings may be wet etching, and other etchings may be dry etching, or all etchings may be wet etching or dry etching. Any combination of wet etching and dry etching may be used as long as a desired fine uneven pattern can be formed.

In the present embodiment, the above-described etching is performed. However, additional etching may be added between or before and after the first and second etchings depending on the constituent material of the copy mold manufacturing blanks.

(Completion of copy mold)
Through the above-described steps, the substrate 1 is cleaned if necessary. In this way, the copy mold 20 as shown in FIG.

(Mold regeneration)
In order to newly manufacture a copy mold, a regeneration process is performed on the mold 30 after imprinting. Specifically, the mold 30 is washed with sulfuric acid / hydrogen peroxide to remove the release layer 31. Thereafter, washing or drying is performed as appropriate. Then, a release layer 31 is newly provided on the mold 30 by applying a release agent again.

<Embodiment 2>
In the first embodiment described above, the copy mold 20 for the optical imprint master mold has been described.
On the other hand, in this embodiment, the copy mold 20 for the thermal imprint master mold will be described. In the following description, parts not particularly mentioned are the same as those in the first embodiment.

First, regarding the substrate used for manufacturing the copy mold 20 for the master mold for thermal imprinting, an SiC substrate resistant to chlorine gas used for dry etching for the hard mask layer 7 may be mentioned.

In addition, about the board | substrate 1 in the case of performing a thermal imprint, in addition to the SiC substrate which is a board | substrate which has tolerance with respect to chlorine-type gas, the tolerance to chlorine-type gas is comparatively weak by giving the following ideas. A silicon wafer can also be used. That is, an SiO ₂ layer is first provided on the silicon wafer 1. By providing the hard mask layer 7 on the SiO ₂ layer, even if the hard mask layer 7 is removed with chlorine gas, the SiO ₂ layer protects the silicon wafer 1 from chlorine gas. Then, the SiO ₂ layer is removed with buffered hydrofluoric acid, that is, a mixed acid composed of ammonium fluoride and hydrofluoric acid. By doing so, a silicon wafer can also be used to produce a thermal imprint mold. Further, those having a SiO ₂ layer as a working layer on the silicon wafer can be used as a substrate. At this time, since a groove is provided in the SiO ₂ layer which is a processed layer, it is preferable to make the SiO ₂ layer thicker than when the silicon wafer 1 is used.
In the present embodiment, description will be made using a disk-shaped SiC substrate.

In the present embodiment, the conductive layer 2 and the chromium nitride layer 3 made of TaHf are formed on the substrate 1.
Next, a resist for thermal imprinting is applied to the hard mask layer 7 in the blanks, and a resist layer 4 is formed to produce blanks with resist used for manufacturing the copy mold 20 in the present embodiment. As the resist for thermal imprinting, a thermoplastic resin that hardens when cooled can be used, but any resin suitable for an etching process to be performed later may be used. In addition, it is preferable that this resin is soft enough to form a fine pattern to be transferred when a mold as an original mold is pressed under heating. This is because when the mold is pressed onto the resist, the resist is easily deformed according to the fine pattern of the mold 30 and the release layer 31, and the fine pattern can be transferred with high accuracy.

After that, by cooling the substrate 1, that is, the resist layer 4, the fine pattern of the mold 30 is transferred to the resist layer 4.

After the fine pattern is transferred, the residual film layer of the resist on the hard mask layer 7 is removed by ashing, and then the copy mold 20 for the imprint master mold is completed by the process described in the first embodiment.

As mentioned above, although embodiment which concerns on this invention was mentioned, the above-mentioned disclosure content shows exemplary embodiment of this invention. The scope of the present invention is not limited to the exemplary embodiments described above. Whether or not explicitly described or suggested herein, those skilled in the art will make various modifications to the embodiments of the present invention based on the disclosure of the present specification. Can be implemented.

(Effect of this embodiment)
In the present embodiment as described above, the following effects can be obtained.
First, the surface energy of the portion in contact with the resist layer provided on the copy mold manufacturing substrate can be reduced by fluorine in the fluorocarbon constituting the release layer. As a result, the mold and the transfer substrate can be released smoothly and with a low release pressure.

Furthermore, by using a plurality of adsorption functional groups for the mold, it can be adsorbed or bonded to the mold at two locations of one molecular chain, and as a result, the adhesion between the mold and the release layer can be improved. it can.

In addition, in the adsorptive functional group, the binding energy that is the basis for the adsorption or binding between the adsorptive functional group and the mold is greater than the binding energy between the adsorptive functional groups in the molecular chain of the release agent compound. In addition, self-aggregation by the release agent compound can be suppressed, and adhesion between the mold and the release layer can be improved.

In addition, a mold release agent compound whose surface free energy value is appropriately changed by changing the heat treatment temperature of the release layer can be satisfactorily filled with a resist without impairing the release property. Transfer pattern defects due to poor filling can be reduced. Therefore, the pattern can be transferred with high accuracy in the imprint process, and as a result, the accuracy and quality of the transfer target (for example, copy mold) are improved, and the quality of the final product obtained thereby is also improved.

コピー The copy mold itself made of quartz produced by using the optical imprint method in this way can be used for any of thermal imprint, room temperature imprint, and optical imprint. In particular, the present embodiment can be suitably applied to patterned media manufactured using optical nanoimprint technology.

Next, the present invention will be specifically described with reference to examples. Of course, the present invention is not limited to the following examples.

<Example>
In this example, a mold 30 made of a quartz substrate provided with a periodic structure having a depth of 30 nm, a recess (groove) of 15 nm, a protrusion (projection) of 35 nm, and a pitch of 50 nm was used.
The mold 30, VERTREL XF-UP (VERTREL is a registered trademark: manufactured by Mitsui-Dupont Fluorochemicals Co.) The following compound was diluted to 0.5 wt% with _{_{_{((C 3 F 6 O)}}} n molecular weight: 500 or more and 6000 5) for 5 minutes.

Thereafter, the mold 30 was pulled up from the solution of the release agent compound at a speed of 120 mm / min. Thus, the release agent compound was applied by the dip method.

At this time, a plurality of samples were prepared, and each sample was heated at a temperature of 25 ° C. to 205 ° C. after being pulled up. Thereafter, the mold 30 was rinsed. Also in this case, the VERTREL XF-UP was used as a rinsing solution, which was immersed for 10 minutes for rinsing.
In this manner, a mold with a release layer for imprinting according to this example was obtained.

Thereafter, a wafer-shaped synthetic quartz substrate (outer diameter 150 mm, thickness 0.7 mm, hereinafter referred to as quartz wafer 1) was used as the substrate 1 for producing the copy mold 20 in this example (FIG. 3A).

Next, the quartz wafer 1 was introduced into a sputtering apparatus. Then, a target made of tantalum (Ta) and hafnium (Hf) (Ta: Hf = 80: 20 atomic ratio) is sputtered with argon gas, and a conductive layer made of a tantalum-hafnium alloy having a thickness of 7 nm is formed on the quartz wafer 1. 2 was formed into a film.

Next, a chromium target was sputtered with a mixed gas of argon and nitrogen to form a chromium nitride layer 3 with a thickness of 2.5 nm (FIG. 3B). Thus, a hard mask layer 7 composed of the conductive layer 2 and the chromium nitride layer 3 was formed on the quartz wafer 1.

Next, an adhesion aid was spin-coated by spin coating on the hard mask layer 7 formed on the quartz wafer 1. After dropping the adhesion aid, the rotation speed was set to 3000 rpm and the quartz wafer 1 was rotated for 60 seconds. After applying the adhesion aid, the quartz wafer 1 was heat-treated on a hot plate at 160 ° C. for 60 seconds.

Next, an ultraviolet photocurable resist 4 for photo-nanoimprinting (PAK-01 manufactured by Toyo Gosei Co., Ltd.) was applied to a thickness of 45 nm by the same spin coating method to form a resist layer 4 (FIG. 3C).

Next, using a nanoimprint apparatus (Molecular Imprints, Inc. Imprio-1100TR), the mold 30 is placed on the quartz wafer 1 on which the ultraviolet light curable resist layer 4 is formed by coating, and left still for 30 seconds. Then, after the filling of the resist 4 into the uneven pattern on the mold 30 was completed, the resist 4 was cured by ultraviolet exposure for 20 seconds (FIG. 3D). Thereafter, the mold 30 and the quartz wafer 1 were pulled apart to release the mold. Thus, the fine concavo-convex pattern on the mold 30 was transferred to the resist layer 4 (FIG. 3E).

Next, the remaining film layer of the resist layer 4 on which the concavo-convex pattern is transferred and formed on the hard mask layer 7 is removed by ashing using plasma of oxygen or argon gas, so as to correspond to the concave portion of the desired fine concavo-convex pattern. The hard mask layer 7 to be exposed was exposed (FIG. 3F).

Next, the quartz wafer 1 on which the hard mask layer 7 having the resist pattern from which the residual film layer has been removed is introduced into a dry etching apparatus, and dry etching is performed while simultaneously introducing Cl ₂ gas and Ar gas. It was. Then, a hard mask layer 7 having a fine pattern was formed (FIG. 3G).

Subsequently, after evacuating the gas used for dry etching on the hard mask layer 7, dry etching using a fluorine-based gas (CHF ₃ : Ar = 1: 9 (flow rate ratio)) in the same dry etching apparatus. Was performed on the quartz wafer 1. At this time, the quartz wafer 1 is etched using the hard mask layer 7 on which the fine pattern is formed using the resist pattern as an original pattern as a mask, and grooves corresponding to the fine uneven pattern (the unevenness is opposite to that of the mold 30). Is applied to the quartz wafer 1.

Then, the resist layer 4 is removed by using sulfuric acid / hydrogen peroxide (concentrated sulfuric acid: hydrogen peroxide solution = 2: 1 volume ratio) composed of concentrated sulfuric acid and hydrogen peroxide solution, to manufacture the copy mold 20 in this embodiment. The mold 10 before removal of the remaining hard mask layer was obtained (FIG. 3H).

After that, the mold 10 before removing the remaining hard mask layer was introduced into the dry etching apparatus used for etching the hard mask layer 7 previously. Then, the hard mask layer 7 on the substrate was removed. Finally, washing was appropriately performed, and thus a copy mold 20 according to the present example, that is, a copy mold made of the quartz wafer 1 corresponding to the fine concavo-convex pattern on the mold 30 (irregularities were reversed) ( FIG. 3 (i)).

<Comparative example>
In order to compare with the above-described examples, in the comparative example, a compound having a modified silane group (product name: OPTOOL (registered trademark) manufactured by Daikin) is used as the mold release agent compound, and the mold release agent is used in the mold 30. After coating, heat treatment was performed at 25 ° C. to 190 ° C. Except this, a mold with a release layer and a copy mold were produced in the same manner as in the example.

<Evaluation>
(1. Surface roughness of mold with release layer)
About the mold with a release layer obtained by the Example and the comparative example, the surface roughness was measured using the atomic force microscope. The result is shown in FIG. FIGS. 5A and 5B are measurement results showing the surface of the mold with a release layer in Examples, and FIG. 5A is a measurement result showing the surface of the mold with a release layer before imprinting. (B) is a measurement result which shows the surface of the mold with a release layer after imprinting once. FIGS. 5C and 5D are measurement results showing the surface of the mold with a release layer in the comparative example, and FIG. 5C is a measurement result showing the surface of the mold with the release layer before imprinting. (D) is a measurement result showing the surface of the mold with a release layer after imprinting once.

In the examples, from FIG. 5A and FIG. 5B, no defects due to self-aggregation were found not only before imprinting but also after imprinting.
On the other hand, in the comparative example, a plurality of defects due to self-aggregation occurred from FIGS. 5 (c) and 5 (d). Moreover, many defects occurred after imprinting.

(2. Imprint durability)
Moreover, it investigated also about the imprint durability in the mold with a release layer which concerns on an Example and a comparative example. Looking at FIG. 6 showing the result (change in the thickness of the release layer with respect to the number of imprints), the thickness of the release layer was maintained in the examples. On the other hand, in the comparative example, when the number of imprints was increased, the thickness of the release layer was reduced. Moreover, when FIG. 7 (surface free energy of a mold release layer) was seen, even if the Example performed imprint several times, the surface free energy was maintained with low.

(3. Release layer thickness)
Moreover, it investigated also about the thickness of the mold release layer in the mold with a mold release layer which concerns on an Example and a comparative example. When FIG. 8 which shows the result was seen, the mold release layer thinner than the comparative example (110 degreeC) of the Example (130 degreeC, 150 degreeC, 190 degreeC, 205 degreeC) was able to be obtained.

(4. Optimization of surface free energy by heat treatment)
Furthermore, the relationship between heat processing temperature and surface free energy was calculated | required. The results are shown in FIG. 9A (Example) and FIG. 9B (Comparative example).

In the examples, from FIG. 9A, when the heat treatment temperature exceeded 170 ° C., the surface free energy did not substantially change. However, in the case of 170 ° C. or lower, the surface free energy could be changed by changing the heat treatment temperature. It has been found that adjusting and optimizing the surface free energy according to the composition of the resist 4 can be used to reliably fill the mold 30 with the resist 4 through the release layer 31 without filling defects.

On the other hand, in the comparative example, as shown in FIG. 9B, the surface free energy cannot be substantially changed even if the heat treatment is changed, and the surface of the release layer 31 depends on the composition of the resist 4. The free energy optimization process could not be performed.

(5. Good filling)
The resist layer 4 made of an ultraviolet photocurable resin on the quartz wafer 1 on which the hard mask layer is formed is brought into contact with the mold with a release layer obtained in the examples and comparative examples by the optical imprint apparatus. I let you. The photograph at that time is shown in FIG. 10A (example) and FIG. 10B (comparative example).
In addition, this mold with a mold release layer is a sample heat-processed at 170 degreeC, after apply | coating the mold release agent compound to a mold.

As can be seen from FIG. 10A, in the example, the resist 4 could be reliably filled over the entire surface of the mold 30 without filling defects.

On the other hand, in the comparative example, as is apparent from FIG. 10B, a filling defect occurred from the center of the left and right sides of the mold 30 to the lower part.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Conductive layer 3 Chromium nitride layer 4 Resist layer 7 Hard mask layer 10 Residual hard mask layer mold 20 Removal mold 30 Mold 31 Release layer for imprint

Claims

In a mold with a release layer in which a release layer is provided in a mold for transferring a predetermined uneven pattern to a pattern forming material by an imprint method,
The main chain of the release agent compound (molecule) constituting the release layer contains a fluorocarbon, and the release agent compound has at least two adsorption functional groups adsorbed or bonded to the mold. In the adsorption functional group, the bond energy between the adsorption functional group and the mold is larger than the bond energy between the adsorption functional groups in the molecular chain of the release agent compound,
A mold with a release layer.
The adsorptive functional group is a functional group capable of hydrogen bonding to the mold;
The mold with a release layer according to claim 1.
The adsorptive functional group is a hydroxyl group, a carboxyl group, an ester group, or any combination thereof;
The mold with a release layer according to claim 1 or 2.
The adsorptive functional groups are provided at both ends of the molecular chain of the release agent compound constituting the release layer;
The mold with a release layer according to any one of claims 1 to 3.
The molecular chain of the release agent compound constituting the release layer has no side chain,
The mold with a release layer according to any one of claims 1 to 4.
The fluorocarbon has (C m F 2m O) n [m is an integer and 1 ≦ m ≦ 7, and n is an integer such that the molecular weight of the (C m F 2m O) n is 500 or more and 6000 or less]. Contain one or more types,
The mold with a release layer according to any one of claims 1 to 5.
In the relationship between the heat treatment temperature for the release layer and the surface free energy of the release layer, the release layer has a region where the value of the surface free energy is constant even when the heat treatment temperature is changed, and the heat treatment A region in which the value of the surface free energy increases or decreases with high and low temperatures, and the release layer after the heat treatment has a region in which the value of the surface free energy increases with a decrease in the heat treatment temperature,
The mold with a release layer according to any one of claims 1 to 6.
The mold is made of a quartz substrate provided with a concavo-convex pattern corresponding to a predetermined pattern;
The mold with a release layer according to any one of claims 1 to 7.
In a mold with a release layer in which a release layer is provided in a mold for transferring a predetermined uneven pattern to a pattern forming material by an imprint method,
The main chain in the molecular chain of the release agent compound constituting the release layer is (C m F 2m O) n [m is an integer and 1 ≦ m ≦ 7, and n is the above (C m F 2m O ) N is an integer in which the molecular weight is 500 or more and 6000 or less].
The release agent compound has at least two hydroxyl groups as adsorption functional groups for the mold, and the hydroxyl groups are provided at both ends of the release agent compound.
In the relationship between the heat treatment temperature for the release layer and the surface free energy of the release layer, the release layer has a region in which the value of the surface free energy is substantially constant even when the heat treatment temperature is changed, A region in which the value of the surface free energy increases or decreases with the level of the treatment temperature, and the release layer after the heat treatment has a region in which the value of the surface free energy increases with a decrease in the heat treatment temperature,
A mold with a release layer.
A method for producing a mold with a release layer according to claim 1,
After applying a release agent compound to the mold, the surface free energy of the release layer is changed by heat treatment to optimize the surface energy of the release layer,
The manufacturing method of the mold with a release layer characterized by these.
The heat treatment is performed at 25 ° C. or more and 250 ° C. or less,
The method for producing a mold with a release layer according to claim 10.
Having a step of rinsing the release layer after the heat treatment,
The manufacturing method of the mold with a release layer of Claim 10 or 11 characterized by these.
A method for producing a copy mold from the mold with a release layer according to claim 1,
Providing a release layer for the mold;
Forming a hard mask layer on a substrate for producing a copy mold; and
Forming a resist layer on the hard mask layer;
Transferring the pattern of the mold to the resist layer;
Etching the hard mask layer using the resist layer to which the pattern of the mold is transferred as a mask;
Etching the substrate for manufacturing the copy mold using the hard mask layer etched using the resist layer as a mask;
A method for producing a copy mold, comprising: