JP5798349B2 - Mold with release layer, method for producing the same, and method for producing the mold - Google Patents

Description

  The present invention relates to a mold with a release layer, a method for producing the mold, and a method for producing the mold, and more particularly, to an original mold used for pattern transfer.

  Conventionally, in a magnetic disk used in a hard disk or the like, a technique has been used in which the magnetic head width is minimized and the data tracks on which information is recorded are narrowed to increase the density. On the other hand, the density of this magnetic disk has been increased and the magnetic influence between adjacent tracks cannot be ignored. For this reason, the conventional method has a limit in increasing the density.

  Recently, a new type of media called patterned media in which data tracks of a magnetic disk are magnetically separated has been proposed. This patterned medium is intended to improve signal quality by removing (grooving) a portion of magnetic material unnecessary for recording.

  As a technique for mass-producing this patterned media, a master mold or a copy mold (also referred to as a working replica) that is copied and copied once or multiple times using the master mold as a master mold is transferred to a transfer material. An imprint technique (or nanoimprint technique) for producing patterned media is known.

  This imprint technique is roughly divided into two types, thermal imprint and optical imprint. Thermal imprinting is a method in which a mold on which a fine pattern is formed is pressed against a thermoplastic resin as a molding material while being heated, and then the molding material is cooled and released to transfer the fine pattern. In the optical imprint, a mold on which a fine pattern is formed is pressed against a photocurable resin that is a molding material, irradiated with ultraviolet light and cured, and then the molding material is released to transfer the fine pattern. Is the method.

  In the imprint mold mentioned here, the master mold itself provided with a fine pattern is not usually used. Instead, a secondary mold formed by transferring the fine pattern of the master mold to another molding material, or formed by transferring the fine pattern of the secondary mold to another molding material 3 The next mold or the like is used. Even if the copy mold is deformed or damaged, if the master mold is safe, the copy mold can be manufactured.

  Now, when actually producing the patterned media as described above, it is necessary to produce this copy mold for each production line. When producing this copy mold, as described above, a master mold having a fine pattern formed thereon (or a copy mold to be an original mold, hereinafter, these molds are collectively referred to as an original mold or simply a mold). Must be pressed against the material to be transferred in the transfer object, and accordingly, the original mold must be released from the material to be transferred, and hence from the transfer object.

In order to smoothly release the original mold from the transfer object, it is known to transfer the pattern after applying a release layer to the surface of the original mold in advance. By providing the mold release layer in this way, the mold mold and the release layer have a certain degree of adhesion, and the mold release layer and the transferred material can be easily released. can do.
For example, Patent Document 1 describes a technique using a surface modifier made of an organic silicone compound having a linear perfluoropolyether structure as a release layer.
Patent Document 2 describes a silicone-based mold release agent having an organopolysiloxane structure as a basic structure. Specifically, polysiloxane containing unmodified or modified silicone oil, trimethylsiloxysilicate, Silicone acrylic resins and the like are mentioned.

JP 2008-537557 A JP 2010-006870 A

As described in Patent Documents 1 and 2, a perfluoropolyether compound is generally used as a release agent for nanoimprint. In these compounds, usually, only one terminal group of the molecular chain of the compound is a functional group for chemically bonding to the substrate surface on which the release layer is to be provided. In addition, a modified silane group is often used as the functional group, which causes dehydration condensation on the substrate surface due to silanol bonds, and the molecular chain of this compound is adsorbed on the substrate surface.
On the other hand, the surface energy of the part of the perfluoropolyether group in the release agent is reduced by fluorine. Then, a portion where the modified silane group in the molecular chain of the compound is not provided, that is, a portion of the perfluoropolyether group and the transferred material come into contact. As a result, the original mold can be smoothly released from the release layer provided on the original mold.

  Certainly, when a terminal-modified silane-based release agent containing a perfluoropolyether group is used, a release layer that adheres firmly to the substrate can be formed, and good imprint resistance can be obtained. On the other hand, since the silicone release agent is highly reactive, it easily reacts with water in an atmosphere other than the surface of the substrate, and there is a possibility that aggregation occurs due to the release agent itself. When aggregation due to the release agent itself occurs in this way, the aggregated portion in the release layer becomes a defect having a considerable physical height. As a result, it is difficult to transfer the pattern with high accuracy during imprinting, which may affect the quality of the final product obtained by copy molding.

  In addition, in compounds having a modified silane group at one end as in Patent Documents 1 and 2, the modified silane group at the end of the molecular chain of the compound is in close contact with the substrate. Further, since the modified silane group is provided only at one end of the molecular chain as shown in FIG. 9 (a), the release chain is formed from the modified silane group to the other end of the molecular chain, that is, the entire molecular chain. This is considered to be oriented in the thickness direction. In this case, the thickness of the release layer depends on the total length of the molecular chain, and when it becomes necessary to form a pattern at the full length level of the molecular chain, it can be expected to affect the pattern accuracy. Specifically, as shown in FIG. 9 (b), when the predetermined pattern size and the length of the molecular chain are approximately the same, a predetermined pattern shape is formed by a release layer having a thickness approximately equal to the pattern size. May change significantly, and may affect the pattern accuracy.

  An object of the present invention has been made in consideration of the above-described circumstances, and has a mold with a release layer capable of transferring a pattern with high accuracy while having sufficient imprint resistance, a method for producing the mold, and a mold. It is to provide a manufacturing method.

According to a first aspect of the present invention, there is provided a mold with a release layer in which a release layer is provided in an original mold for transferring a predetermined pattern to a transfer object by imprinting, and the compound contained in the release layer The main chain in the molecular chain contains a fluorocarbon, and the molecular chain of the compound has at least two adsorption functional groups adsorbed to the original mold, and the adsorption functional group includes the adsorption functional group. The mold with a release layer is characterized in that the bond energy that is the source of adsorption between the mold and the mold is larger than the bond energy between the adsorbed functional groups in the molecular chain of the compound.
According to a second aspect of the present invention, in the invention according to the first aspect, the adsorption functional group is a hydroxyl group, a carboxyl group, an ester group, or any combination thereof.
According to a third aspect of the present invention, in the invention according to the first or second aspect, the adsorptive functional groups are provided at both ends of the molecular chain of the compound contained in the release layer. And
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the fluorocarbon includes (C _m F _2m O) _n [m is an integer and 1 ≦ m ≦ 7, n is an integer such that (C _m F _2m O) _{n has} a molecular weight of 500 or more and 6000 or less].
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 compound contained in the release layer has no side chain.
According to a sixth aspect of the present invention, there is provided a mold with a release layer in which a release layer is provided in an original mold for transferring a predetermined pattern to a transfer object by imprinting, and the compound contained in the release layer The main chain in the molecular chain is (C _m F _2m O) _n [m is an integer and 1 ≦ m ≦ 7, and n is the molecular weight of the (C _m F _2m O) _n is 500 or more and 6000 or less. Integer] is included in one or more types, the compound has at least two hydroxyl groups as adsorption functional groups for the original mold, and the hydroxyl groups are provided at both ends of the molecular chain of the compound. In the adsorptive functional group, the binding energy that causes the adsorption between the adsorptive functional group and the original mold is larger than the binding energy between the adsorptive functional groups in the molecular chain of the compound. And said that no.
According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the master mold is formed of a quartz substrate provided with a groove corresponding to a predetermined pattern. To do.
According to an eighth aspect of the present invention, in the method for manufacturing a mold with a release layer in which a release layer is provided in an original mold for transferring a predetermined pattern to a transfer object by imprinting, the release from the original mold is performed. After the mold agent is applied, it has a heat treatment step of heat-treating the original mold at 100 ° C. or more and 250 ° C. or less, and the main chain in the molecular chain of the compound contained in the release layer contains fluorocarbon The compound has at least two or more adsorption functional groups with respect to the original mold, and in the adsorption functional group, the binding energy that causes the adsorption between the adsorption functional group and the original mold is a molecule of the compound. It is a manufacturing method of the mold with a release layer characterized by being larger than the bond energy of the adsorption | suction functional groups in a chain | strand.
According to a ninth aspect of the present invention, in the invention described in the eighth aspect, a rinsing treatment is performed on the release layer after the heat treatment step.
According to a tenth aspect of the present invention, there is provided a method for producing a mold from an imprint mold provided with grooves corresponding to a predetermined pattern, wherein the mold layer is provided on the mold. And forming a hard mask layer on the mold substrate, forming a pattern forming resist layer on the hard mask layer, and patterning the original mold by optical imprinting or thermal imprinting. A step of transferring to the resist layer; a step of releasing the original mold from the resist layer; and a step of etching the hard mask layer using the resist layer to which a predetermined pattern is transferred as a mask; The main chain in the molecular chain of the compound contained in the release layer contains a fluorocarbon, and the compound is At least two adhering functional groups, and in the adsorbing functional group, the binding energy that is the source of adsorption between the adsorbing functional group and the original mold is more than the binding energy of the adsorbing functional groups in the molecular chain of the compound. The mold manufacturing method is also characterized by a large size.

  According to the present invention, it is possible to transfer a pattern with high accuracy while having sufficient imprint resistance.

It is a conceptual diagram for demonstrating a mode that the adsorption functional group in the molecular chain which comprises the mold release agent which concerns on this embodiment has couple | bonded with the substance on an original mold, (a) is a hydroxyl group at the terminal of a molecular chain (B) is a case where the hydroxyl group is other than the end of the molecular chain, (c) is a state in which van der Waals force is acting on the main chain, (d) is a case where there are three hydroxyl groups, e) shows a state where there are four hydroxyl groups. It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the mold with a release layer which concerns on this embodiment. It is a cross-sectional schematic diagram for demonstrating the process of manufacturing a 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 observed using the scanning electron microscope about the mold with a release layer obtained by the Example and the comparative example, (a) (b) is an Example, (c) (d) is a comparison. It is a photograph which shows the surface of the mold with a release layer in an example. It is a graph which shows the result of having investigated the imprint durability about the mold with a release layer obtained by the Example and the comparative example based on the layer thickness of a release layer. It is a graph which shows the result of having investigated the imprint durability based on the surface free energy of a mold release layer 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 a mold release layer about the mold with a mold release layer obtained by the Example and the comparative example. In the comparative example, (a) is a conceptual diagram for explaining how the pattern size is changed by providing a release layer, and (b) is an element when a silane group exists only at one end of the molecular chain. It is a conceptual diagram for demonstrating the mode of adsorption | suction with a mold mold and a mold release layer.

  The present inventors have studied various types of release layers that can suppress the occurrence of defects due to self-aggregation while having imprint resistance. In this study, the present inventors paid attention to the modified silane group that contributes to the adhesion to the substrate and at the same time contributes to self-aggregation in the conventionally used silicone release agents.

  The inventors of the present invention have a relationship between the binding energy that causes the adsorption of the modified silane group (that is, the adsorption functional group to the substrate) and the original mold and the binding energy between the adsorption functional groups during self-aggregation. Pay attention. As a result, if the bond that is the source of adsorption between the original mold and the adsorption functional group is more stable than the bond between the adsorption functional groups during self-aggregation, it becomes a problem during imprinting. It was found that self-aggregation inside the release layer can be suppressed.

  Furthermore, the present inventors paid attention to the fact that the conventional modified silane group as shown in FIG. 9B is provided only at one end of the compound that forms the release layer for imprinting. And by having two or more said adsorption functional groups, as shown in FIG. 1, it discovered that several adsorption functional groups played the role of the anchor in a molecular chain. As a result, it has been found that the thickness of the release layer is not limited to the total length of the molecular chains inside the release layer, thereby improving the pattern accuracy.

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

  In the present embodiment, a process for producing a copy mold by providing a release layer on the original mold will be described. However, when performing pattern transfer using this copy mold, a release layer may naturally be provided in the copy mold. In the present embodiment, the mold includes an original mold for imprinting (that is, a master mold) and a copy mold produced by the original mold.

(Preparation of the original mold)
As shown in FIG. 2, a mold 30 is prepared as an original mold of a pattern to be transferred to the copy mold 20. The master mold 30 may be any mold as long as it can be used as an imprint mold, but is preferably a translucent material (for example, quartz or sapphire) because the later-described exposure can be performed from the master mold 30. . If the copy mold substrate has translucency, exposure can be performed from the copy mold substrate side. In this case, the material of the master mold 30 can be used even if it does not have translucency (for example, silicon wafer, nickel). In addition, the release layer 31 is not provided directly on the substrate, but the release layer 31 is provided on the layer of another material with respect to the original mold 30 provided with a layer made of another material on the substrate. It doesn't matter. In this embodiment, a case where a quartz substrate provided with a groove corresponding to a predetermined pattern is described.

  The predetermined pattern provided on the quartz substrate may be on the micron order, but may be on the nano order from the viewpoint of the performance of electronic devices in recent years, or the final pattern produced by an imprint mold or the like. This is preferable when considering the performance of the product.

  When a predetermined pattern provided on the original mold 30 is transferred by imprinting, a pattern opposite to the predetermined pattern is formed on the copy mold. Therefore, if the pattern of the copy mold is a pattern to be finally obtained, a pattern opposite to the pattern may be formed on the original mold 30. Moreover, after transferring a pattern to a temporary copy mold, the same pattern as the original mold 30 may be obtained by transferring the temporary copy mold pattern to another copy mold.

(Installation of release layer on the original mold)
And in this embodiment, as shown in FIG. 2, the mold release layer 31 is provided by apply | coating a mold release agent to this original mold 30, the part in which the predetermined pattern was formed at least. By providing the release layer 31, when the resist layer 4 provided on the copy mold manufacturing substrate 1 shown in FIG. 3 described later and the original mold 30 (and thus the release layer 31) are brought into contact with each other, The release layer 31 can be easily separated from the resist layer 4. As a result, the master mold 30 can be smoothly released from the resist layer 4, the throughput can be improved, and pattern twisting of the master mold 30 and the resist layer 4 can be suppressed. Hereinafter, the release layer 31 will be described in detail.

(Summary of compound composition of release layer)
First, the compound contained in the release layer 31 according to the present embodiment includes a main chain portion that contributes to release and an adsorption functional group for adsorbing to the original mold 30.

(Main chain part of release layer compound)
The main chain in this molecular chain contains a fluorocarbon. Fluorine in the fluorocarbon can reduce the surface energy of the surface of the release layer 31, that is, the portion in contact with the resist layer 4 provided on the copy mold manufacturing substrate 1. As a result, release can be performed smoothly.

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 compound, the surface energy of the part in contact with the resist layer in the release layer 31 can be reduced. In addition, as shown in FIGS. 1 (a) and 1 (b), the entire molecular chain becomes a random coil shape due to the presence of the ether group, and the flexibility of the molecular chain can be improved. If the flexibility of the molecular chain is improved, the layer thickness depends on the total length of the molecular chain due to the orientation in the layer thickness direction. It will be relaxed by the flexibility. 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.
When m is 1 or more, the flexibility is exhibited moderately, so that the distance between molecular chains after adsorbing to the original mold 30 can be appropriately close, and molecular chains composed of moderately dense fluorocarbons. Thus, the surface 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 as described above. 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 the (C _m F _2m O) _n is 500 or more and 6000 or less.
If (C m _F 2m _O) molecular weight of _n is 500 or more, also eliminates the adsorptive functional groups to each other molecular chain is too short is likely to self-aggregation. Furthermore, the intermolecular force in the direction in which the molecular chains adsorbed on the original mold 30 are brought close to each other can be maintained, and the surface energy of the release layer 31 is sufficiently increased by the molecular chains made of moderately dense fluorocarbons. Can be lowered.
Further, 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 layer compound)
In addition, the compound contained in the release layer 31 has at least two adsorption functional groups for the original mold. As described above, the release layer 31 is required to smoothly release from the resist layer provided on the copy mold manufacturing substrate, and at the same time, the release layer 31 is in physical contact with the resist layer. Imprint durability when releasing is required. Specifically, the release layer 31 needs to have sufficient adhesion to the original mold 30. If the adhesiveness is not sufficient, the mold release layer 31 may be peeled off from the original mold during imprinting and remain on the resist layer, which may affect the pattern accuracy of the copy mold. is there. In this embodiment, by providing a plurality of adsorption functional groups for the master mold, two adsorption functional groups can be attached to one molecular chain in the compound even if the master mold 30 and one adsorption functional group cannot be firmly adsorbed. If so, anchors can be provided to the original mold 30 at two locations of one molecular chain, and as a result, adhesion to the original mold 30 can be enhanced.

  In order to sufficiently exert the anchor effect on the molecular chain as described above, the adsorbing functional group is a portion close to both ends of the molecular chain of the compound contained in the release layer 31 (FIG. 1B). ), Preferably at both ends (FIG. 1 (a)). If the adsorptive functional group is in a portion close to both ends of the molecular chain, it is possible to suppress the orientation of the entire length of the molecular chain in the layer thickness direction, and thus the layer thickness can be greatly reduced as compared with the conventional case. Moreover, the adhesiveness between the master mold 30 and the release layer 31 can be improved by firmly bonding to the master mold 30 at two distant locations in the molecular chain.

  When the adsorptive functional group is present in a portion close to both ends in the molecular chain of the compound contained in the release layer, the following effects can be expected though it is speculated. That is, when the adsorptive functional group is adsorbed to the master 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 master mold 30, and a physical force in the direction toward the master mold 30 is the main force. Inferred to work against the chain.

  Further, when the adsorptive functional group is provided in a portion close to both ends of the molecular chain as described above, as shown in FIG. It is preferable to have. By doing so, the number of anchor portions in the molecular chain can be increased, and as a result, the layer thickness can be further reduced. In particular, from the balance of adhesion, releasability, ease of use, and suppression of self-aggregation, as shown in FIGS. 1D and 1E, the adsorbing functional groups have 3 or 4 in total. Is preferred.

  The adsorptive 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 to the master mold 30 is lower than that of the modified silane group, as described above, in this embodiment, two adsorption functional groups are provided in one molecular chain, and the master mold 30 Sufficient adhesiveness can be ensured. In view of the binding energy described later, that is, the adhesiveness and the self-aggregation hardly occur, the adsorptive functional group is preferably a hydroxyl group.

  In addition, although it demonstrated that the said adsorption functional group adsorb | sucks to the original mold 30, when the said adsorption functional group consists of a hydroxyl group, a carboxyl group, an ester group, or any combination of these, on the original mold 30 It is considered that a strong bond is formed by causing dehydration condensation between water present in the water and the adsorbing functional group. Further, when the master mold is made of a quartz substrate, oxygen on the quartz substrate surface and the adsorption functional group cause hydrogen bonding, and as a result, the adhesion between the master mold 30 and the release layer 31 can be further improved. it can. In addition to the functional groups listed above, as described above, it is considered that a strong bond is formed by causing dehydration condensation with water on the master mold 30.

(Binding energy of adsorption functional group)
Further, in the adsorptive functional group, the binding energy that is the source of adsorption between the adsorptive functional group and the original mold is made larger than the binding energy between the adsorptive functional groups in the molecular chain of the compound. As described above, in imprinting, the self-aggregation of the release agent inside the release layer is one of the factors that reduce the pattern accuracy. However, by using a compound having such a binding energy relationship as a release agent, even if the adsorption functional group causes self-aggregation, the bond between the substance present on the original mold and the adsorption functional group. Self-aggregation is released because the energy is higher. Finally, the substance present on the original mold 30 and the adsorption functional group are bonded. As a result, the adhesiveness between the original mold 30 and the release layer 31 can be improved by suppressing self-aggregation by the release agent.

(Additive)
In addition, this mold release agent may contain the well-known substance which can be added to a mold release agent besides the above compounds.

(Application of mold release agent to the original mold)
A mold release agent having the above compound is applied on the master mold 30 so as to provide the release layer 31 on the master 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 more. Within this time range, the release agent can be sufficiently applied to the master mold 30. A sufficient time can be secured for the adsorptive functional group to adsorb to the original mold 30.
Moreover, it is preferable to carry out the pulling-up speed after dipping at 80-200 mm / min. If the speed is not more than the upper limit, the uniformity during the application of the release agent 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)
Thus, after apply | coating a mold release agent to the original mold 30, it is preferable to heat-process with respect to this original mold 30 at 100 to 250 degreeC. This is because the release layer 31 is densified by removing the solvent in the release agent, and the adhesion between the original mold 30 and the release layer 31 is improved. Also, within this temperature range, adhesion can be improved without causing thermal decomposition of the compound in the release agent. Furthermore, by performing heat treatment in the above temperature range, it is possible to easily adsorb two or more adsorption functional groups to the master mold 30 as shown in FIG. In other words, two or more adsorptive functional groups can be easily combined with the substance on the original mold 30. As a result, the adhesiveness between the master mold 30 and the release layer 31 can be further improved, and the film thickness can be prevented from depending on the total length of the molecular chain.
Specific examples of the heating means include a clean oven and a hot plate.

(Rinse treatment)
After performing the heat treatment as described above, a rinsing process is performed on the original mold 30 with the release layer 31. This rinsing process is performed to wash away the molecules of the compound that have not been adsorbed to the original mold 30.

  In this embodiment, it is meaningful to perform the rinsing process after performing the heat treatment as described above. This is because, if rinsing is performed without performing the above-described heat treatment, molecular chains that are not sufficiently adsorbed to the original mold 30 will be washed away from the substrate 1. However, after the above heat treatment, each molecular chain can be sufficiently adsorbed to the original mold 30. Therefore, only molecular chains that are not adsorbed to the original mold 30 can be washed away. In this way, it is possible to suppress an increase in surface energy caused by leaving unused adsorption functional groups in the release layer 31, and as a result, it is not necessary to deteriorate the release property. Any rinse solution that does not dissolve the release layer 31 may be used.

  The above is the process for providing the release layer 31 on the master mold 30. Hereinafter, a process for producing a copy mold by optical imprinting using the original 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 as long as it can be used as the copy mold 20 and may be made of the same material as the former mold 30 described above. Moreover, the same material as the original mold 30 may be used. In addition, when performing a light imprint, it is preferable that it is a translucent board | substrate from a viewpoint of light irradiation to a to-be-transferred material. As this translucent substrate 1, glass substrates, such as a quartz substrate, are mentioned. In addition, as long as the original mold has translucency, a non-translucent substrate such as a Si substrate may be used.

Further, as for the shape of the substrate 1, it is preferably a disc shape. This is because the resist can be applied uniformly while rotating the disk substrate 1 when applying the resist. The shape may be other than a disk shape, and may be a rectangle, a polygon, or a semicircle.
In the present embodiment, description will be made using a disk-shaped quartz substrate 1.

(Formation of hard mask layer)
Next, as shown in FIG. 3B, the quartz substrate 1 is introduced into a sputtering apparatus. In the present embodiment, a target made of an alloy of tantalum (Ta) and hafnium (Hf) is sputtered with argon gas to form a conductive layer 2 made of tantalum-hafnium alloy, and a groove formed on the substrate 1 It is preferable to use the lower layer (conductive layer 2) of the hard mask layer 7 having a fine pattern corresponding to.

  In addition, as a material of the conductive layer 2, what is used as a well-known conductive layer may be used. As an example, a compound containing Ta as a main component can be mentioned. In this case, Ta compounds such as TaHf, TaZr, TaHfZr, and alloys thereof are suitable. On the other hand, at least one element of hafnium (Hf) and zirconium (Zr) or a compound thereof (for example, HfZr) can be selected, and these materials are used as base materials, for example, B, Ge, Nb, Si, C, etc. , N and other sub-materials can be selected. In the present embodiment, the conductive layer 2 made of a tantalum-hafnium (TaHf) alloy will be described.

  Next, in the present embodiment, from the viewpoint of preventing oxidation, the conductive layer 2 is not exposed to the atmosphere, and a chromium target is sputtered with a mixed gas of argon and nitrogen to form a chromium nitride layer 3. The upper layer (antioxidant layer 3 for conductive layer) in the hard mask layer 7 having a pattern is preferably used.

  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 during film formation, but any other compound that can be used as the antioxidant layer may be used. . For example, a molybdenum compound, 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 quartz substrate 1.

The “hard mask layer” in the present embodiment is composed of a single layer or a plurality of layers, can protect a portion where a groove corresponding to a pattern is to be formed, and is a mask for etching the groove on the substrate. It shall refer to the layered material used for. However, 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.
Thus, what provided the hard mask layer 7 on the board | substrate is called mask blanks in this embodiment.

(Formation of resist layer)
After appropriately cleaning and baking the hard mask layer 7 in the mask blank, as shown in FIG. 3C, a photo imprint resist is applied to the hard mask layer 7 in the mask blank. Then, the resist layer 4 is formed, and a mask blank with resist used for manufacturing the copy mold 20 in this embodiment is manufactured. Examples of the resist for photoimprinting include a photocurable resin, particularly an ultraviolet curable resin. Any photocurable resin may be used as long as it is suitable for an etching process performed later.

  In addition, the thickness of the resist layer 4 at this time is preferably such a thickness that the resist serving as a mask remains until various etchings are completed.

  Note that an adhesive layer may be provided on the hard mask layer 7 before the resist layer 4 is provided. By providing the adhesion layer, it is possible to prevent the resist layer 4 from being peeled off during imprinting or etching.

(Placing the original mold on the resist layer)
After appropriately baking the resist layer 4, as shown in FIG. 3 (d), an original mold 30 on which a fine pattern and a release layer 31 are formed is disposed on the resist layer 4. To do. At this time, if the resist layer 4 is liquid, it is only necessary to place the original mold 30. When the resist layer 4 is in a solid shape, the resist layer 4 may be soft enough to press the original mold 30 against the resist layer 4 and transfer a fine pattern.

(Pattern transfer by exposure)
Thereafter, the fine pattern of the original mold 30 is transferred to the resist layer 4 using an ultraviolet light irradiation device. At this time, the ultraviolet light exposure is usually performed from the original mold 30 side, but may be performed from the substrate 1 side when the mask blank substrate 1 is a translucent substrate.

  At this time, in order to prevent a transfer failure due to a positional shift between the master mold 30 and the mask blank, preparation for providing an alignment mark groove on the substrate may be performed.

(Removal of residual film layer in resist layer)
After transferring the fine pattern, the original mold 30 is released from the mask blank with resist as shown in FIG. Then, the remaining film layer of the resist on the chromium nitride layer 3 is removed by ashing using a plasma of a gas such as oxygen or ozone. Thus, a resist pattern corresponding to a desired fine pattern is formed as shown in FIG. Note that a groove is formed on the substrate 1 in a portion where the resist is not formed.

(First etching)
Next, the substrate 1 having a resist pattern formed on the substrate 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 when the inflow amount of oxygen gas is 5% or less of the entire inflow gas.

  By this etching, a hard mask layer 7 having a fine pattern is formed as shown in FIG. Note that the etching end point at this time is determined by using a reflection optical end point detector.

(Second etching)
Subsequently, after evacuating the gas used in the first etching, the quartz substrate 1 is subjected to a second etching using a fluorine-based gas in the same dry etching apparatus. At this time, the quartz substrate 1 is etched using the hard mask layer 7 as a mask, and grooves corresponding to the fine pattern are formed on the substrate 1 as shown in FIG. Before and after that, the resist is removed with an alkaline 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 performed on the quartz substrate 1, and the hard mask layer 7 having the fine pattern is formed on the portion other than the groove of the quartz substrate 1. In this way, the mold 10 before removing the remaining hard mask layer 7 is produced.

(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 removing process is performed, and thereby the imprint mold 20 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. Further, when the pattern size is in the micron order, wet etching may be introduced according to the pattern size, such as wet etching at the micron order stage and dry etching at the nano order stage.

  In the present embodiment, the first and second etchings are performed. However, additional etching may be added between the first and second etchings depending on the constituent material of the mask blank.

(Completion of copy mold)
After removing the hard mask layer 7 other than the groove forming portion through the above steps, the substrate 1 is cleaned if necessary. In this way, the copy mold 20 as shown in FIG.

(Regeneration of original mold)
In order to newly produce a copy mold, a regeneration process is performed on the original 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 is newly provided on the original mold 30 by applying the release agent again.

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, release can be performed smoothly.

  Furthermore, by using a plurality of adsorption functional groups for the master mold, it is possible to bond to the master mold 30 at two locations of one molecular chain, and as a result, the adhesion to the master mold 30 is improved. be able to.

  In addition, in the adsorptive functional group, the binding energy that is the source of adsorption between the adsorptive functional group and the original mold is made larger than the binding energy between the adsorptive functional groups in the molecular chain of the compound. Self-aggregation by the mold can be suppressed, and the adhesion between the original mold and the release layer can be enhanced.

  Further, the copy mold itself produced using optical imprinting in this way can be used for both thermal imprinting and optical imprinting, and can also be applied to nanoimprint technology. In particular, the present embodiment can be suitably applied to patterned media manufactured using an imprint technique.

<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 mask blank, and the resist layer 4 is formed to produce a mask blank with resist used for manufacturing the copy mold 20 in the present embodiment. . Examples of the resist for thermal imprinting include resins that are cured when cooled, and any resin that is suitable for an etching process to be performed later may be used. The resin preferably has such a softness that a fine pattern to be transferred is formed when the original mold is pressed. When the original mold is pressed onto the resist, the resist can be easily deformed according to the fine pattern of the original mold 30 and the release layer 31, and the fine pattern can be accurately transferred by the subsequent cooling process. This is because it can.

  Thereafter, the fine pattern of the original mold 30 is transferred to the resist layer 4 using a cooling processing apparatus.

  After transferring the fine pattern, the remaining 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.

  In the present invention, the “substrate” is for forming an original mold as shown in the embodiment, and any substrate can be used as long as the release layer according to this embodiment can be provided thereon. For example, a substrate, and another compound layer provided on the substrate.

  As mentioned above, although embodiment which concerns on this invention was mentioned, said 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.

  Next, an Example is shown and this invention is demonstrated concretely. Of course, the present invention is not limited to the following examples.

<Example>
In the present embodiment, an original mold 30 made of a quartz substrate provided with a line-and-space pattern having a half pitch 25 nm periodic structure with a depth of 30 nm, a line of 15 nm, and a space of 10 nm is used. The molecular weight of the following compound ((C ₃ F ₆ O) _n ) diluted to 0.5 wt% with VERTREL XF-UP (VERTREL is a registered trademark, manufactured by Mitsui DuPont Fluorochemical Co., Ltd.): 500 to 6000 5) for 5 minutes.
Thereafter, the original mold 30 was pulled up at a speed of 120 mm / min.

  Thus, the release agent was applied by the dip method. At this time, a plurality of samples were prepared, and each sample was heat-treated at a temperature of 130 ° C. to 205 ° C. Thereafter, the original mold 30 was rinsed. In this case, too, Vertrel XF-UP was used as a rinse solution, and rinse treatment was performed for 10 minutes. Thus, the mold with a release layer which concerns on a present Example was obtained.

  Thereafter, a disc-shaped synthetic quartz substrate (outer diameter 150 mm, thickness 0.7 mm) was used as the substrate 1 for producing the copy mold 20 of this example (FIG. 3A). This quartz substrate 1 was introduced into a sputtering apparatus.

  A target composed of an alloy of tantalum (Ta) and hafnium (Hf) (Ta: Hf = 80: 20 atomic ratio) was sputtered with argon gas, and a tantalum-hafnium alloy having a thickness of 7 nm was formed on the substrate used in the examples. A conductive layer 2 made of was formed.

  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, an adhesion aid was applied on the hard mask layer 7 formed of the conductive layer 2 and the chromium nitride layer 3 formed on the substrate 1 by spin coating. The number of rotations during this coating was 3000 rpm, and coating was performed for 60 seconds.

  After applying the adhesion aid, the substrate 1 was baked at 160 ° C. for 60 seconds.

  Using an imprint apparatus (Imprio 1100 manufactured by MII), an ultraviolet photocurable resist layer 4 (PAK-01 manufactured by Toyo Gosei Co., Ltd.) for photoimprinting was applied to a thickness of 45 nm by an ink jet method (FIG. 3C).

  Next, the master mold 30 was placed on the photocurable resist layer 4 and subjected to ultraviolet exposure for 20 seconds (FIG. 3D). After transferring the fine pattern by ultraviolet exposure (FIG. 3E), the remaining film layer of the resist on the hard mask layer 7 is removed by ashing using plasma of oxygen and argon gas to correspond to a desired fine pattern. A resist pattern was formed (FIG. 3F).

Next, the substrate 1 on which the hard mask layer 7 having a resist pattern was formed was introduced into a dry etching apparatus, and dry etching (Cl ₂ ) was performed while simultaneously introducing Cl ₂ gas and Ar gas. 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 substrate 1. At this time, the quartz substrate 1 was etched using the hard mask layer 7 as a mask, and grooves corresponding to the fine pattern were formed on the substrate.

  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).

  Thereafter, the mold 10 before removing the remaining hard mask layer after removing the resist layer 4 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, and washing was appropriately performed to produce a copy mold 20 in this example (FIG. 3 (i)).

<Comparative example>
In order to compare with the above-mentioned Examples, in the comparative example, a compound having a modified silane group (product name: manufactured by OPTOOL (registered trademark) Daikin) was used as a mold release agent at 110 ° C. during the application of the mold release agent. Heat treatment was performed. Except this, a mold with a release layer and a copy mold were produced in the same manner as in the example.

<Evaluation>
About the mold with a release layer obtained by the Example and the comparative example, it observed using the scanning electron microscope. The result is shown in FIG. FIGS. 5A and 5B are photographs showing the surface of the mold with a release layer in Examples, and FIG. 5A is a photograph showing the surface of the mold with a release layer before imprinting. ) Is a photograph showing the surface of the mold with a release layer after imprinting once. Moreover, FIG.5 (c) (d) is a photograph which shows the surface of the mold with a release layer in a comparative example, (c) is a photograph which shows the surface of the mold with a release layer before imprinting, (D) is a photograph showing the surface of the mold with a release layer after imprinting once.

In the examples, from FIG. 5 (a) and FIG. 5 (b), no defects due to self-aggregation were found after imprinting as well as before 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.

  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 (release layer thickness) showing the result, the layer 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 release layer was peeled off. Moreover, when FIG. 7 (surface free energy of a mold release layer) is seen, even if imprinting was performed several times in the Example, the surface free energy remained low and the favorable mold release property was maintained.

  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 was thinner than the comparative example in the Example.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Conductive layer 3 Chromium nitride layer 4 Resist layer 7 Hard mask layer 10 Mold before remaining hard mask layer removal 20 Copy mold 30 Original mold 31 Release layer

Claims (10)

In a mold with a release layer in which a release layer is provided in an original mold for transferring a predetermined pattern to a transfer object by imprinting,
The main chain in the molecular chain of the compound contained in the release layer contains a fluorocarbon,
The molecular chain of the compound, and hydroxyl group free of modified silane group as the adsorptive functional groups which is adsorbed to the original mold, a carboxyl group, to perforated or at least two or more of the ester group A mold with a release layer. The mold with a release layer according to claim 1, wherein the adsorptive functional group is a hydroxyl group .   3. The mold with a release layer according to claim 1, wherein the adsorptive functional groups are provided at both ends of a molecular chain of a compound contained in the release layer. The fluorocarbon has (C _m F _2m O) _n [m is an integer and 1 ≦ m ≦ 7, and n is an _{integer in which} the molecular weight of the (C _m F _2m O) _n is 500 or more and 6000 or less]. The mold with a release layer according to any one of claims 1 to 3, wherein one or a plurality of kinds are included.   The mold with a release layer according to any one of claims 1 to 4, wherein the molecular chain of the compound contained in the release layer does not have a side chain. In a mold with a release layer in which a release layer is provided in an original mold for transferring a predetermined pattern to a transfer object by imprinting,
The main chain in the molecular chain of the compound contained in the release layer is (C _m F _2m O) _n [m is an integer and 1 ≦ m ≦ 7, and n is the value of (C _m F _2m O) _n One or more types of integers having a molecular weight of 500 or more and 6000 or less]
The compound does not contain a modified silane group as an adsorption functional group for the original mold and has at least two hydroxyl groups,
The release layer with the mold, wherein the hydroxyl groups at both ends are provided in the molecular chains of said compounds.   The mold with a release layer according to any one of claims 1 to 6, wherein the original mold is made of a quartz substrate provided with grooves corresponding to a predetermined pattern. In the method for producing a mold with a release layer in which a release layer is provided in an original mold for transferring a predetermined pattern to a transfer object by imprinting,
After applying a mold release agent to the master mold, the base mold has a heat treatment step of performing heat treatment at 100 ° C. or more and 250 ° C. or less,
The main chain in the molecular chain of the compound contained in the release layer contains a fluorocarbon,
The compounds are based on mold and free of modified silane group as the adsorptive functional groups to hydroxyl groups, carboxyl groups, of the release layer with the mold, characterized in that the organic or at least two or more of the ester group Production method.   The method for manufacturing a mold with a release layer according to claim 8, wherein a rinse treatment is performed on the release layer after the heat treatment step. A method for producing a mold from an imprint mold provided with grooves corresponding to a predetermined pattern,
Providing a release layer for the original mold;
Forming a hard mask layer on the mold substrate, and forming a pattern forming resist layer on the hard mask layer;
Transferring the pattern of the original mold to the resist layer by optical imprinting or thermal imprinting;
Releasing the original mold from the resist layer;
A step of etching the hard mask layer using the resist layer to which a predetermined pattern is transferred as a mask,
The main chain in the molecular chain of the compound contained in the release layer contains a fluorocarbon,
The compounds and hydroxyl group free of modified silane group as the adsorptive functional groups to the original mold, the mold fabrication method which is characterized in that chromatic either at least two or more of a carboxyl group, an ester group.