TW201313429A - Mold release processing method for nanoimprinting molds, production method employing the mold release processing method, nanoimprinting mold, nanoimprinting method, and method for producing patterned substrates - Google Patents

Abstract

A mold release processing method for a mold (1) includes: preparing a mold release processing substrate (5) coated with a mold release agent (6); causing a mold main body (12) having adsorbed water (2) on the surface thereof and the mold release processing substrate (5) to approach each other until a contact state in which the upper portions of protrusions of a pattern (13) of protrusions and recesses are in contact with the mold release agent (6); maintaining the contact state until a mold release layer (14), having a thickness distribution in which the thickness of the mold release layer (14) at the side surfaces (Ss) of the pattern (13) of protrusions and recesses becomes thinner from the top surfaces (St) of the protrusions toward the bottom surfaces (Sb) of the recesses due to the mold release agent (6) becoming diffused in the adsorbed water (2), is formed; and causing the mold main body (12) and the mold release processing substrate (5) to move away from each other such that the upper portions of the protrusions separate from the mold release agent (6) on the mold release processing substrate (5).

Description

Release method for nanoimprint mold, manufacturing method using the same, nanoimprint method, and method for manufacturing patterned substrate

The present invention relates to a mold having a pattern of protrusions and recesses on a surface, a method of manufacturing the mold, a nanoimprint method, and a method of manufacturing a patterned substrate.

In applications for manufacturing magnetic recording media such as discrete track media (DTM) and bit patterned media (BPM) and semiconductor devices, the pattern is transferred to the nanoimprint method. The pattern transfer technique applied to the resist on the object to be treated has a high degree of expectation.

Specifically, the nanoimprint method, that is, a mold on which a concavo-convex pattern is formed (generally referred to as a mold, a stamper, or a stencil) is pressed against a resist applied to a substrate as an object to be processed. . Pressing the prototype onto the resist causes the resist to mechanically deform or flow, thereby accurately transferring the fine pattern. Once the mold is produced, the nano-scale fine structure can be overmolded in a simple manner. Therefore, the nanoimprint method is an economical transfer technique that produces almost no hazardous waste and emissions. Therefore, there is a high expectation for applying the nanoimprint method to various fields.

In nanoimprinting, a mold release treatment is performed to form a release layer in which a release agent is bonded (including physical bonds and chemical bonds) to the surface of the mold body such that the residual resist is not separated when the mold is separated from the resist It will remain on the surface of the mold (Patent Documents 1 to 4). More specifically, Patent Document 2 discloses that a release treatment is performed only on the top surface of the convex portion of the concave-convex pattern on the mold. Methods. Patent Document 3 discloses a method of bonding a large amount of release agent to a concave portion of a concave-convex pattern to cause mold release property to become uneven over the entire concave-convex pattern. Patent Document 4 discloses a method of making the amount of the releasing agent bonded to the bottom surface of the concave portion smaller than the amount of the releasing agent bonded to the top surface of the convex portion.

However, it is known that the release agent is gradually peeled off from the surface of the mold as the nanoimprint operation is repeatedly performed. In these cases, it is preferable to perform a mold release treatment to form a release layer on the mold, for example, each time a predetermined imprint operation is performed. Further, if the demolding treatment is performed outside the nanoimprinting apparatus, the productivity of the nanoimprinting is remarkably lowered. Therefore, the demolding treatment is preferably carried out together with the nanoimprinting treatment inside the nanoimprinting apparatus. A transfer technique in which a release agent for applying a concavo-convex pattern of a mold main body to a release-treated substrate (Patent Document 2) is a release treatment which can be easily performed inside a nanoimprinting apparatus.

[Previous Technical Literature] [Patent Literature] [Patent Document 1]

U.S. Patent No. 6,309,580

[Patent Document 2]

Japanese Patent No. 4317375

[Patent Document 3]

Japanese Unexamined Patent Publication No. 2008-179034

[Patent Document 4]

Japanese Unexamined Patent Publication No. 2009-226750

However, in the method disclosed in Patent Document 2, only the concave-convex pattern is The top surface of the convex portion is subjected to mold release treatment, so there is a problem that the surface release property of other surfaces is poor. In the invention of Patent Document 2, this is not a problem from the viewpoint of the fact that the resist pattern is required to have an aspect ratio larger than that of the concave-convex pattern. However, in the general nanoimprint operation, from the viewpoint of suppressing the occurrence of defects in the resist pattern, it is often desirable to have high releasability on the entire surface of the concavo-convex pattern.

In view of the above, the present invention has been developed. SUMMARY OF THE INVENTION An object of the present invention is to provide a mold release treatment method for producing a nano imprint mold which can be easily carried out inside a nano imprint apparatus and which improves the mold release property of the entire surface of the concavo-convex pattern. Another object of the present invention is to provide a method of manufacturing a nanoimprinting mold to which the demolding method is applied.

It is still another object of the present invention to provide a mold capable of achieving precise processing, a nanoimprint method, and a method of manufacturing a patterned substrate using nanoimprinting used in the manufacture of a patterned substrate.

The mold release treatment method of the present invention which achieves the above object is a method of forming a release layer on the surface of a mold main body, wherein the mold main body has a fine concavo-convex pattern on its surface, which is characterized by comprising: preparing a coating The mold release treatment substrate; the mold body having the adsorbed water on the surface and the mold release substrate are brought close to each other until the contact state, wherein the convex portion of the concave and convex pattern is in contact with the release agent; maintaining the contact state until the mold release is formed Layer, the thickness distribution of the release layer is The thickness of the release layer at the side of the concave-convex pattern is thinned from the top surface of the convex portion toward the bottom surface of the concave portion due to diffusion of the release agent into the adsorbed water; and the mold main body and the release-treated substrate are separated from each other such that the convex portion is The upper portion is separated from the release agent on the release treated substrate.

The release treatment method of the present invention is preferably carried out inside a nanoimprinting apparatus.

The method for producing a nanoimprinting mold of the present invention is a method for producing a mold having a mold main body having a fine concavo-convex pattern on the surface and a release layer on the surface of the mold main body, comprising: preparing a coating release agent Dissolving the substrate; bringing the mold body having the adsorbed water on the surface and the release-treated substrate to each other until the contact state, wherein the upper portion of the convex portion of the concave-convex pattern is in contact with the release agent; maintaining the contact state until the release is formed The thickness distribution of the release layer is such that the thickness of the release layer at the side of the concave-convex layer is thinned from the top surface of the convex portion toward the bottom surface of the concave portion due to the diffusion of the release agent into the adsorption water; and the mold body and the mold release are made. The treatment substrates are separated from each other such that the upper portion of the protrusions is separated from the release agent on the release treatment substrate.

The method for producing a nanoimprinting mold of the present invention is preferably carried out inside a nanoimprinting apparatus.

The nanoimprinting mold of the present invention comprises: a mold main body having a fine concavo-convex pattern on the surface; and a release layer on the surface of the mold main body; and characterized in that the thickness distribution of the release layer is the release layer in the unevenness At the side of the pattern The thickness is thinned from the top surface of the convex portion toward the bottom surface of the concave portion.

In the mold of the present invention, the thickness distribution of the release layer may be such that the thickness at the side surface is reduced from the thickness as thick as the thickness at the top surface to the thickness as thick as the thickness at the bottom surface.

In the mold of the present invention, the thickness distribution of the release layer may be such that the thickness at the top surface is in the range of 1 nm to 5 nm, and the thickness at the bottom surface is in the range of 0.1 nm to 1 nm and The thickness at the top surface is 70% or less.

In addition, the nanoimprint method of the present invention is characterized by comprising: using a mold as described above; coating a nanoimprint substrate with a resist; and pressing the mold on the nanoimprint substrate coated with a resist Surface; and separating the mold from the nanoimprint substrate.

Preferably, the nanoimprint method of the present invention applies a mold release treatment to the mold after a predetermined number of pressing steps or according to the degree of abrasion of the release layer, the mold release treatment comprising: preparing a coating release agent Dissolving the substrate; bringing the mold body having the adsorbed water on the surface and the release-treated substrate to each other until the contact state, wherein the upper portion of the convex portion of the concave-convex pattern is in contact with the release agent; maintaining the contact state until the release is formed The thickness distribution of the release layer is such that the thickness of the release layer at the side of the concave-convex pattern is thinned from the top surface of the convex portion toward the bottom surface of the concave portion due to the diffusion of the release agent into the adsorption water; The mold main body and the release-treated substrate are separated from each other such that the upper portion of the convex portion is separated from the release agent on the release-treated substrate.

In the nanoimprint method of the present invention, both the step of pressing the mold against the nanoimprint substrate and the step of performing the mold release treatment are preferably performed inside the nanoimprinting apparatus.

The method for fabricating a patterned substrate of the present invention is characterized by comprising: forming a resist film on a substrate to be processed by the nanoimprint method described above, transferring the concave-convex pattern to the resist film; The etchant film is etched as a mask to form a concavo-convex pattern corresponding to the concavo-convex pattern transferred onto the resist film.

The mold release treatment method and the mold manufacturing method of the present invention are characterized by comprising the steps of: preparing a release treatment substrate coated with a release agent; and bringing the mold main body having the adsorbed water on the surface and the release treatment substrate close to each other until a contact state in which an upper portion of the convex portion of the concave-convex pattern is in contact with the release agent; the contact state is maintained until a release layer is formed, and the thickness distribution of the release layer is such that the thickness of the release layer at the side of the concave-convex pattern is diffused by the release agent to The water is adsorbed and thinned from the top surface of the convex portion toward the bottom surface of the concave portion; and the mold main body and the release-treated substrate are separated from each other such that the upper portion of the convex portion is separated from the release agent on the release-treated substrate. Thereby, the release layer can be formed not only on the top surface of the convex portion of the concave-convex pattern but also on the side surface of the convex portion and the bottom surface of the concave portion. Therefore, the release treatment can be easily performed inside the nanoimprinting apparatus and the mold release property on the entire surface of the concavo-convex pattern is improved.

Further, the nanoimprinting mold of the present invention is characterized in that it has a release layer, and the thickness distribution of the release layer is the thickness of the release layer at the side of the concave-convex pattern. The degree is thinned from the top surface of the convex portion toward the bottom surface of the concave portion. Since the release layer is formed on the entire surface of the concavo-convex pattern, the release property of the entire surface is high. Therefore, it is possible to perform precise processing in the manufacture of a patterned substrate to which nanoimprint is applied.

Furthermore, the nanoimprint method of the present invention and the method of manufacturing a patterned substrate are carried out using the mold of the present invention, which has high mold release property over the entire surface of the concavo-convex pattern. Therefore, it is possible to perform precise processing in the manufacture of a patterned substrate to which nanoimprint is applied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the invention is not limited to the embodiments described below. Note that in the drawings, the dimensions of the constituent elements drawn are different from their actual dimensions to facilitate their visual recognition.

[Release processing method for nano imprinting mold, manufacturing method of nano imprinting mold, and nano imprinting mold]

1 is a schematic cross-sectional view illustrating the structure of a mold 1 according to an embodiment of the present invention. 2 to 6 are schematic cross-sectional views illustrating steps of a method of manufacturing the mold 1.

The mold release treatment for the mold 1 of the present embodiment comprises the steps of: preparing the mold main body 12 having the concave-convex pattern 13; preparing the release treatment substrate 5 coated with the release agent 6 (Fig. 2); and adsorbing on the surface The mold main body 12 having the water 2 and the release-treated substrate 5 are brought close to each other until the upper portion of the convex portion in the contact state of the concave-convex pattern 13 is in contact with the release agent 6 (FIG. 3); the contact state is maintained until the formation of the release layer 14 is formed. The thickness distribution of the release layer 14 is The thickness of the release layer 14 at the side Ss of the concavo-convex pattern 13 is diffused into the adsorbed water 2 by the release agent 6, and the top surface St from the convex portion is thinned toward the bottom surface Sb of the recess (Fig. 5); The mold main body 12 and the release-treated substrate 5 are separated from each other such that the upper portion of the convex portion is separated from the release agent 6 on the release-treated substrate 5 (Fig. 6).

Note that when the release layer 14 is formed on the mold main body 12, the mold 1 is constructed. Therefore, the mold release treatment method is actually the same as the mold 1 manufacturing method.

The mold 1 of the present embodiment obtained by the above-described mold release treatment method and mold manufacturing method is provided with: a mold main body 12 having a fine uneven pattern 13 on the surface; and a peel formed on the entire surface of the mold main body 12. The mold layer 14, as illustrated in Figure 1. The thickness distribution of the release layer 14 is such that the thickness of the release layer 14 at the top surface St of the convex portion is greater than the thickness at the bottom surface Sb of the concave portion, and the thickness of the release layer 14 at the side Ss of the concave-convex pattern 13 is The top surface St is thinned toward the bottom surface Sb.

(mold body)

The material of the mold body 12 may be: metals such as tantalum, nickel, aluminum, chromium, steel, tantalum, and tungsten; oxides, nitrides, and carbides thereof. Specific examples of support material portion 12 comprises silicon oxide, alumina, quartz glass, Pyrex (Pyrex ^TM) glass, and soda glass.

The shape of the concavo-convex pattern 13 is not particularly limited and may be selected as appropriate depending on the intended use of the nanoimprint mold. An example of a typical pattern is a line-space pattern, as illustrated in FIG. The length of the line-space pattern, the width of the protrusion W1, the distance W2 between the protrusions, and the bottom of the protrusion from the bottom of the recess The height H (depth of the recess) is set as appropriate in the line-space pattern. For example, the width W1 of the line is in the range of 10 nm to 100 nm, more preferably in the range of 20 nm to 70 nm, and the distance W2 between the lines is in the range of 10 nm to 500 nm. More preferably, it is in the range of 20 nm to 100 nm, and the height H of the line is in the range of 10 nm to 500 nm, more preferably in the range of 30 nm to 100 nm. Further, the shape of the convex portion constituting the concave-convex pattern 13 may be a point having a rectangular, circular or elliptical cross section.

The mold body 12 described above can be manufactured, for example, by the following procedure. First, a ruthenium substrate is coated with a photoresist by a spin coating method or the like to form a resist layer having an acrylic resin (such as a PHS (polyhydroxystyrene) type chemically amplified resist. As a main component, a novolak resin or PMMA (polymethyl methacrylate). Next, a laser beam (or electron beam) is irradiated onto the crucible substrate while being adjusted according to the desired concavo-convex pattern to expose the pattern on the surface of the photoresist layer. Subsequently, the photoresist layer is developed to remove the exposed portions. Finally, the photoresist layer after the exposed portion is removed is selectively etched by reactive ion etching (RIE) or the like using the photoresist layer as a mask to obtain a mold body having a predetermined concavo-convex pattern. In the case of obtaining a platform-type mold body 12 having a mesa portion and a flange portion, a base material having a stepped outer peripheral portion is employed, and a bump is formed on the platform portion by the steps described above pattern.

(adsorbed water on the surface of the mold body)

Adsorbed water 2 adsorbed on the surface of the mold main body 12 is in the present invention Very important. More specifically, as will be described later, the releasing agent 6 is diffused to the concave-convex pattern 13 by the phenomenon that the meniscus (the liquid bridge formed in the minute gap between the objects) is formed by the capillary action of the adsorbed water 2 On the surface. The "adsorbed water" refers to water molecules contained in the environment around the mold main body 12 and attached to the surface of the mold main body 12 in a liquid phase.

In the present embodiment, the environment around the mold main body 12 is adjusted as necessary to cause the adsorbed water 2 to adhere to the surface of the mold main body 12. The thickness of the layer (adsorbed water layer) formed of the adsorbed water 2 is set as appropriate depending on the thickness of the release layer 14 to be formed. Specifically, the relationship between the thickness of the adsorbed aqueous layer and the thickness of the release layer 14 is set such that the thickness of the adsorbed aqueous layer is about half the thickness of the release layer to be formed. In the present invention, the thickness of the adsorbed aqueous layer is preferably in the range of from 0.3 nm to 3 nm, and the thickness is more preferably in the range of from 1 nm to 2 nm. The reason for setting the above upper limit is because the possibility of condensation is high in an environment where the thickness of the adsorbed water layer exceeds 3 nm. If condensation occurs, it is difficult to form a uniform aqueous adsorbed layer. The reason for setting the above lower limit is that if the thickness of the adsorbed aqueous layer is less than 0.3 nm, the diffusion efficiency of the releasing agent 6 is remarkably lowered. It is effective to set conditions which contribute to adhesion of the adsorbed water 2 to the surface of the mold main body 12 to increase the coating rate of the release agent 6 or to reduce the release treatment time. Examples of the method of setting such conditions include: performing a surface treatment on the surface of the mold main body 12 to change its properties to make the surface hydrophilic; and increasing the relative humidity of the environment in which the imprinting is performed. A surface treatment method for changing the properties of the surface of the mold main body 12 to make the surface hydrophilic: a wet cleaning method using a chemical agent; a dry cleaning method using plasma or UV ozone; and a method of combining wet washing and dry cleaning methods law. From the viewpoint of setting the thickness of the adsorbed aqueous layer within the range described above, the relative humidity is preferably in the range of 20% to 90%, and more preferably in the range of 40% to 90%. In some cases, no relative intentional control is required, and the relative humidity satisfies the above conditions. Alternatively, it is possible to control the relative humidity to a desired value by supplying dry air or humid air to adjust the environment around the mold main body 12. Depending on the hydrophilic nature of the surface of the mold body 12, the humidity of the environment, the temperature of the environment, etc., the adsorbed water 2 will reach an equilibrium state (the amount of adsorbed water molecules is equal to the amount of vaporized water molecules). In the equilibrium state, the adsorbed aqueous layer will maintain a constant thickness on the surface of the mold body 12.

Alternatively, the adsorbed water 2 may be attached to the surface of the mold main body 12 by coating the surface with water. In this case, at the stage when the adsorbed water 2 coated on the surface of the mold main body 12 reaches an equilibrium state, or at a stage before the equilibrium state is reached (that is, a stage in which water molecule evaporation is dominant), the mold is made The main body 12 and the release agent 6 are in contact with each other. In the case where the surface of the mold main body 12 is applied with water, it is preferable that the mold main body 12 and the release agent 6 are brought into contact with each other at a stage when the adsorbed water 2 applied to the surface of the mold main body 12 reaches an equilibrium state. This is because in the case where the mold main body 12 and the releasing agent 6 are brought into contact with each other at the stage before the equilibrium state is reached, it is difficult to control the thickness of the adsorbed water layer on the entire surface of the mold main body 12 to be uniform. Since the amount of adsorbed water is different from the concave portion in the convex portion constituting the concave-convex pattern 13, it is difficult to make the thickness of the adsorbed water layer uniform. Particularly in the case where the surface of the mold main body 12 is hydrophilic, the adsorbed water collects in the concave portion but does not gather at the convex portion. In contrast, when the adsorbed water 2 coated on the surface of the mold main body 12 reaches an equilibrium state, the fluctuation of the thickness of the adsorbed water layer caused by the aforementioned factors is reduced. small. Therefore, in the stage when the adsorbed water 2 on the surface of the mold main body 12 reaches an equilibrium state, when the mold main body 12 and the releasing agent 6 are brought into contact with each other, an adsorbed aqueous layer having a uniform thickness can be realized.

(release agent)

The release agent 6 is preferably a fluorine compound. The fluorine compound is preferably a fluorine series decane coupling agent. Commercially available release agents such as Optool DSX manufactured by Daikin Industries KK and Novec EGC manufactured by Sumitomo 3M KK can be utilized. 1720.

Alternatively, other known fluororesins, hydrocarbon series lubricants, fluorine series lubricants, fluorine series decane coupling agents, and the like can be used.

An example of a fluorine series resin is polytetrafluoro ethylene (PTFE).

Examples of hydrocarbon series lubricants include: carboxylic acids such as stearic acid and oleic acid; esters such as butyl stearate; sulfonic acids such as octadecyl sulfonic acid; phosphates such as monooctadecyl phosphate; Alcohols such as stearyl alcohol and oleyl alcohol; carboxylic acid amides such as decylamine stearate; and amines such as stearylamine.

Examples of the fluorine series lubricant include a lubricant in which a part or all of the alkyl group of the aforementioned hydrocarbon series lubricant is replaced by a fluoroalkyl group or a perfluoropolyether group. The perfluoropolyether group may be a perfluorooxymethylene polymer, a perfluoroethylene oxide polymer, a perfluoro-n-propylene oxide polymer (CF ₂ CF ₂ CF ₂ O) _n , a perfluorooxidized isopropylene polymer. (CF(CF ₃ )CF ₂ O) _n , a copolymer of the above polymer, or the like. Here, the subscript n indicates the degree of polymerization.

Other fluoro-series decane coupling agents preferably have at least one, and preferably one to ten, alkoxyalkyl and perchloroalkyl groups per molecule, and have a molecular weight in the range of from 200 to 10,000. Examples of alkoxyalkylalkyl groups are -Si(OCH ₃ ) ₃ and -Si(OCH ₂ CH ₃ ) ₃ . Meanwhile, examples of the chlorodecyl group include -Si(Cl) ₃ . Specific examples of the fluorine-series decane coupling agent include: heptadecafluoro-1,1,2,2-tetrahydroindoletrimethoxydecane; pentafluorophenylpropyldimethylchlorodecane; and tridecafluoro-1. 1,2,2-tetrahydrogenyltriethoxydecane; and tridecafluoro-1,1,2,2-tetrahydrogenyltrimethoxydecane.

(release treatment substrate)

The release-treated substrate 5 is a substrate on which the release agent 6 is applied before the mold main body 12 is subjected to a release treatment. The shape, structure, size, material, and the like of the release-treated substrate 5 are not particularly limited. However, a highly flat substrate is preferred. The release treatment substrate 5 may be a single layer structure or a laminate structure. The material of the release-treated substrate 5 can be selected as appropriate from known materials. Examples of such materials include: ruthenium, nickel, aluminum, glass, and resins. These materials may be used singly or in combination of two or more kinds. The release treatment substrate 5 may be self-made or may utilize a commercially available substrate. The thickness of the release-treated substrate 5 is not particularly limited. However, the thickness of the release-treated substrate 5 is preferably 0.05 mm or more, and more preferably 0.1 mm or more. The reason why the lower limit is set as described above is because when the top surface St of the convex portion of the mold main body 12 and the releasing agent 6 are in contact with each other, if the thickness of the release-treated layer 5 is less than 0.05 mm, the release-treated substrate 5 will be scratched. It may not ensure a uniform contact state.

The method of applying the release agent 6 to the release-treated substrate 5 is not particularly limit. Examples of the coating method include: a vapor deposition method; a spin coating method + a dip coating method; a spray coating method; and an inkjet method. The film thickness of the release agent 6 in the coated state on the release-treated substrate 5 is preferably in the range of from 1 nm to 100 nm, more preferably in the range of from 2 nm to 50 nm, and is most preferably In the range of 3 nm to 30 nm.

(contact step between the mold body and the release agent)

After the release agent 6 is applied onto the release-treated substrate 5, the mold main body 12 is brought close to the release-treated substrate 5 so as to achieve a contact state in which only the upper portion of the convex portion of the concave-convex pattern 13 is in contact with the release agent 6. The "upper portion of the convex portion" means a convex portion including the top surface St of the convex portion and a convex portion within a predetermined distance from the top surface St. This is because it is difficult to control the film thickness of the release layer 14 if the convex portion contacts the release agent 6 so that the entire convex portion is immersed in the release agent 6. Therefore, it is preferable that the overall configuration is designed such that the total volume of the releasing agent 6 is smaller than the total volume corresponding to the gap of the recesses, so that only the portion adjacent to the top surface St contacts the releasing agent 6. If such a configuration is designed, even if the mold main body 12 and the release-treated substrate 5 are close to each other and pressed against each other, there will be a gap in the recess, so that the entire convex portion will not be immersed in the release agent 6. Alternatively, the distance between the mold main body 12 and the release-treated substrate 5 may be adjusted so that the upper portion of the convex portion of the concave-convex pattern 13 contacts the release agent 6 without designing the total volume of the release agent 6 in advance. A wide range of film thickness control of the release layer 14 on the side surface Ss of the convex portion can be obtained by realizing a contact state in which only the upper portion of the convex portion of the concave-convex pattern 13 is in contact with the release agent 6.

After the mold main body 12 is aligned with the release-treated substrate 5 to have a predetermined relative positional relationship, they are brought into contact with each other. Alignment mark The mold body 12 is aligned with the release treatment substrate 5. After the contact state is achieved, pressure can be applied as necessary.

The amount of the release agent 6 applied to the release-treated substrate 5, the shape of the pattern on the mold main body 12, the amount of the adsorbed water 2 on the mold main body 12, and the relative, depending on various conditions, such as the type of the release agent 6, Humidity, as appropriate, sets the length of time during which the mold body 12 is brought into contact with the release agent 6. The length of time for maintaining the mold main body 12 in contact with the releasing agent 6 is preferably in the range of 1 second to 1 hour, more preferably in the range of 10 seconds to 10 minutes, and still more preferably in the range of 1 minute to 5 minutes. .

(diffusion of release agent)

The diffusion of the release agent 6 due to the meniscus phenomenon will now be described. 3 illustrates the manner in which the top surface St of the convex portion of the concave-convex pattern 13 of the mold main body 12 is in contact with the surface of the release agent 6. In this case, a meniscus is formed in the gap between the side surface Ss of the convex portion and the surface of the releasing agent 6. Subsequently, the release agent 6 is spread over the entire surface of the concavo-convex pattern 13, as illustrated in Fig. 4 (indicated by reference numeral 6a in Fig. 4). The amount of the release agent 6a to be diffused depends on the length of time during which the top surface St of the support protrusion is in contact with the surface of the release agent 6, the amount of adsorbed water 2, and the like. During the time when the mold main body 12 is in contact with the release agent 6, the release agent continues to diffuse, and the release agent 6 finally diffuses to the bottom surface Sb of the concave portion of the concave-convex pattern 13. The release agent 6a on the uneven pattern 13 is bonded to the surface thereof to constitute the release layer 14.

The diffusion of the release agent 6 proceeds from the top surface St of the convex portion of the concave-convex pattern to the bottom surface Sb of the concave portion. Therefore, it is possible to impart a certain distribution of the thickness of the release layer 14 from the top surface St to the bottom surface Sb. In making the mold body 12 and the release agent 6 long In the case of time contact, the amount of the released release agent 6a will become saturated. Therefore, it is also possible to form the release layer 14 having a uniform thickness. The diffusion of the release agent 6 is a physical phenomenon which is performed regardless of the width of the concave portion of the concave-convex pattern 13. Therefore, even if the concave-convex pattern includes the recesses having different widths, the length of time during which the release agent 6 can be sufficiently diffused at the bottom surface of the recess having a larger width can be formed at all by simply maintaining the contact state for a period of time. A release layer 14 having a uniform thickness at the bottom surface of the recess.

(release layer)

The release treatment of the surface of the mold is completed, and after the mold main body 12 is brought into contact with the release agent 6 for a predetermined period of time, the release layer 14 is formed by separating the mold main body 12 from the release treatment substrate 5.

The thickness of the release layer 14 is preferably in the range of from 1 nm to 5 nm. In the case of imparting a certain distribution of the thickness of the release layer, the thickness distribution may be such that the thickness at the top surface is in the range of 1 nm to 5 nm, and the thickness at the bottom surface is 0.1 nm to 1 nm. Within the range, and is 70% or less of the thickness at the top surface. Note that the "thickness" of the release layer 14 is the average thickness of the top surface St or the bottom surface Sb.

The difference between the thickness of the release agent at the top surface St of the projection and the bottom surface Sb of the recess and the thickness of the thickness at the bottom surface Sb with respect to the thickness at the top surface St were measured by the following method. First, a line-space pattern is formed on the mold body 12 separately from the concavo-convex pattern 13 for measuring the thickness such that the probe tip of an Atomic Force microscope (AFM) can reach its recess. The bottom surface Sb. The AFM uses a probe to measure the shape of the concave and convex pattern, and specifies the data obtained by the measurement as a reference. data. Next, the same measurement is performed on the mold 1 on which the mold release treatment has been performed, and the data on the step height is compared with the reference material. Thereby, the difference in the thickness of the release agent at each of the top surface St of the convex portion and the bottom surface Sb of the concave portion can be calculated. Next, the thickness of the release layer 14 at the flat portion of the mold body 12 without any protrusions or recesses is measured by ellipsometry. The thickness of the release layer at the flat zone corresponds to the thickness of the release layer at the top surface St of the projection. The thickness at the bottom surface Sb of the recess can be calculated based on the difference in thickness between the top surface St and the release agent at the bottom surface Sb obtained by the method described above, and the thickness of the release agent at the top surface St. The percentage of the thickness at the top surface St.

The thickness distribution from the top surface St of the convex portion to the bottom surface Sb of the concave portion on the side surface Ss of the convex portion is measured by the following method. First, a resist pattern is formed by embossing a mold main body 12 which has not been subjected to mold release treatment, and a mold main body 12 which has been subjected to mold release treatment. Subsequently, the cross-sectional shape of the concavo-convex pattern in each resist pattern was measured by a scanning electron microscope. The inclination angle and the width of the convex portion were obtained from the measured cross-sectional shape, and the case where the mold release treatment was performed was compared with the case where the mold release treatment was not performed. Thereby, the thickness distribution of the release layer 14 on the side wall Ss from the top surface St of the convex portion to the bottom surface Sb of the concave portion can be calculated.

Hereinafter, the operational effects of the present invention will be described. The mold release treatment method of the present invention can be carried out inside a general nanoimprint apparatus by providing a release treatment substrate in a nanoimprinting apparatus instead of a nanoimprint substrate. By performing the mold release processing method inside the nanoimprinting apparatus, it is possible to avoid the trouble of removing the mold 1 from the inside of the nanoimprinting apparatus and processing the mold 1 in the respective apparatus to perform the mold release treatment, thereby improving the nanometer. The productivity of the imprinting operation. Also The risk of foreign substances adhering to the mold 1 when removing and transferring the mold is avoided.

In the mold release treatment method of the present invention, it is possible to form the release layer 14 such that its thickness gradually becomes thinner from the upper surface St of the convex portion toward the bottom surface Sb of the concave portion. By utilizing this ability, the demolding method of the present invention makes it possible to bring the taper angle of the concave-convex pattern 13 of the mold main body to approximately 90 degrees, but the extent of this effect will vary depending on the processing conditions. Further, the thickness distribution of the release layer 14 actually improves the right angle of the concave-convex pattern 13 of the mold 1 coated by the release layer 14, thereby further increasing the height of the pattern.

Specifically, the shape of the resist pattern obtained by imprinting the resist film becomes more advantageous in the step of processing the substrate after the imprinting step because of its large right angle. However, since the line width of the concave-convex pattern becomes narrower, it is difficult to form a concave-convex pattern having a high right angle when manufacturing a mold. Therefore, the shape of the concave-convex pattern on the mold will become tapered and its tip will be narrowed. The formation of a resist pattern formed using such a mold necessarily also becomes tapered. In such cases, the problem is that the processing accuracy of the substrate will be reduced. Therefore, it is desirable to correct the concavo-convex pattern on the mold to increase its right angle in the step after pattern formation. According to the mold release treatment method of the present invention, the release layer 14 can be formed which is gradually thinned from the top surface St of the convex portion to the bottom surface Sb of the concave portion. Therefore, it is possible to implement such a corrective step.

The mold release treatment method of the present invention utilizes the diffusion of the release agent 6 in the adsorbed water 2. Therefore, the release layer 14 can be formed so as to be gradually thinned from the top surface St of the convex portion to the bottom surface Sb of the concave portion at the same ratio regardless of the convex portion of the concave-convex pattern 13 and the width of the concave portion.

It is conceivable to use a solvent other than water to diffuse the release agent 6. Of course However, it is preferred to use water for the following reasons. In the case of using a solvent other than water to diffuse the releasing agent 6, it is necessary to use a liquid phase component of the solvent in the environment and a liquid phase on the surface of the mold main body in the same manner as in the case of using water as described above. A balance between the components is achieved. Therefore, it is necessary to improve the affinity of the surface of the mold body with respect to the organic solvent so that the organic solvent is adsorbed on the surface of the mold body. However, it is often the case that the properties of the surface of the mold body (generally composed of a material such as tantalum, metal, oxide, quartz) are hydrophilic after the cleaning step before the mold release treatment is changed. That is, since the surface of the mold main body is hydrophilic after cleaning, the organic solvent will easily volatilize. Therefore, it is extremely difficult to maintain the organic solvent on the surface of the mold as an adsorption solvent and to form a meniscus of an organic solvent on the surface of the mold body having low affinity.

In the case where a chemical vapor deposition method is employed as an alternative method, a certain thickness distribution of the release layer from the top surface St of the convex portion to the bottom surface Sb of the concave portion can be imparted. However, in the case of applying the chemical vapor deposition method, when the opening of the recess is large, the thickness of the release layer becomes large. Therefore, the chemical vapor deposition method is effective in the case where the mold has a concavo-convex pattern and the recesses of the concavo-convex pattern have openings of uniform size. However, in the case where the mold has a concavo-convex pattern and the recesses of the concavo-convex pattern have openings of different sizes, the application of the release layer may become insufficient at a portion where the opening is small. Further, if the deposition conditions are suitable for the thickness of the release layer at the portion where the opening of the recess is small, the thickness of the release layer becomes excessive at the portion where the opening is large. Such problems do not occur in the mold release treatment method of the present invention. Therefore, the demolding treatment method of the present invention can be effectively used as the top surface St to the concave portion of the release layer from the convex portion. A method of distributing a certain thickness of the bottom surface Sb.

[Nano imprint method using the mold of the present invention]

Hereinafter, an embodiment of a nanoimprint method to which the mold of the present invention is applied will be described.

The nanoimprint method of this embodiment employs a mold 1, such as the mold 1 illustrated in FIG. A nanoimprint substrate formed of quartz is coated with a photocurable resist. Next, the mold 1 is pressed against the surface of the nanoimprint substrate coated with the resist. Subsequently, ultraviolet light is irradiated from the back surface of the nanoimprint substrate to cure the resist, and the mold 1 is separated from the resist.

(resist)

The resist is not particularly limited. In the present embodiment, a resist prepared by adding a photopolymerization initiator (2% by mass) and a fluoromonomer (0.1% by mass to 1% by mass) to the polymerizable compound can be used. An antioxidant (about 1% by mass) may be additionally added as necessary. The resist produced by the above procedure can be cured by ultraviolet light having a wavelength of 360 nm. Regarding the resist having poor solubility, it is preferred to add a small amount of acetone or ethyl acetate to dissolve the resin, followed by removal of the solvent. Note that in the present embodiment, the resist is a photocurable material. However, the invention is not limited to such configurations, and either a thermally curable material may be employed.

Examples of the polymerizable compound include: benzyl acrylate (Biscoat #160, manufactured by Osaka Organic Chemical Industries, KK), ethyl carbitol acrylate (than Cisco #190, Polypropylene glycol diacrylate (manufactured by Osaka Organic Chemical Industries, KK) Aronix M-220, manufactured by Toago Seiki Co., Ltd. (TOAGOSEI KK), and Trimethylolpropane PO-denatured triacrylate (Onyx M-310, by Toagosei KK) Manufacturing). Further, the compound A represented by the following Chemical Formula 1 can also be used as the polymerizable compound.

Examples of the photopolymerization initiator include an alkylphenyl ketone type photopolymerization initiator such as 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-( 4-morpholinyl)phenyl]-1-butanone (Yanjiagu 379, manufactured by Toyotsu Chemiplas KK)

Further, the compound B represented by the following Chemical Formula 2 can be used as a fluorine monomer.

In the case where the resist is applied by the inkjet method, it is preferred to use the compound A represented by Chemical Formula 1, the Onyx M-220, and Yanjiagu by mixing at a mass ratio of 48:48:3:1. 379 and a photocurable resist formed of the compound B represented by Chemical Formula 2.

In the present invention, the resist material has a viscosity in the range of 8 centipoise (cP) to 20 centipoise, and the surface energy of the resist material is in the range of 25 millinewtons/meter to 35 millinewtons/meter. Here, the viscosity of the resist material was measured at 25 ± 0.2 ° C using a RE-80L rotational viscometer (manufactured by Touki Industries K.K.). The rotation speed during the measurement is: 100 rpm when the viscosity is greater than or equal to 0.5 centipoise and less than 5 centipoise; 50 rpm when the viscosity is greater than or equal to 5 centipoise and less than 10 centipoise; 10 rpm when it is greater than or equal to 10 centipoise and less than 30 centipoise; and 10 rpm when the viscosity is greater than or equal to 30 centipoise and less than 60 centipoise. Using H. Schmitt et al., "UV nanoimprint materials: surface energies, residual layers, and imprint quality", vacuum science The surface energy of the resist material is measured by the technique disclosed in Journal of Technology B (J. Vac. Sci. Technol. B.), Vol. 25, No. 3, pp. 785-790, 2007. Specifically, the surface energy of the ruthenium substrate which has been subjected to UV ozone treatment and whose surface has been treated by Optool DSX (manufactured by Daikin Industries KK) is measured, and then according to the resist material and The contact angle of the substrate is used to calculate the surface energy of the resist material.

(nano imprinted substrate)

In the case where the mold 1 has light transmissivity, the nanoimprint substrate is in its shape It is not limited in terms of shape, structure, size or material and can be selected according to the intended use. The expression "transparency" refers to the extent to which light that is sufficiently cured by the resin film when light enters the base side opposite to the side on which the resin film is formed. The surface of the nanoimprint substrate which is the target of the pattern transfer is a surface coated with a resist. Regarding the shape of the substrate, for example, in the case of manufacturing a data recording medium, a substrate having a disk shape can be utilized. Regarding the structure of the substrate, a single layer substrate may be employed, or a laminate substrate may be employed. Regarding the material of the substrate, the material may be selected from known materials for the substrate, such as ruthenium, nickel, aluminum, glass, and resins. These materials can be used alone or in combination. The thickness of the substrate is not particularly limited and may be selected according to the intended use. However, the thickness of the substrate is preferably 0.05 mm or more, and more preferably 0.1 mm or more. If the thickness of the substrate is less than 0.05 mm, the substrate may be deflected during contact with the mold, resulting in a failure to ensure a uniform close contact state.

Meanwhile, in the case where the mold 1 does not have light transmissivity, the quartz substrate is preferably used as a nanoimprint substrate to enable exposure of the resist. The quartz substrate is not particularly limited as long as it has light transmittance and a thickness of 0.3 mm or more, and may be selected as appropriate according to the intended use. Regarding the light transmittance, it is sufficient for light having a wavelength of 200 nm or more to be at least 5% of light transmittance from the side of the substrate opposite to the side on which the resin film is formed to the side of the substrate on which the resin film is formed. A quartz substrate having a surface coated with a decane coupling agent may be employed. Further, a quartz layer laminated with a metal layer formed of chromium, tungsten, tantalum, titanium, nickel, silver, platinum, gold, or the like and/or a metal oxide layer formed of CrO ₂ , WO ₂ , TiO ₂ or the like may be used. Substrate. The thickness of the metal layer or the metal oxide layer is preferably 30 nm or less, and more preferably 20 nm or less. If the thickness of the mask layer exceeds 30 nm, the UV transmittance is deteriorated, and the resist curing failure is more likely to occur. Note that the surface of the laminate layer may be coated with a decane coupling agent. The thickness of the quartz substrate is preferably 0.3 mm or more. If the thickness of the quartz substrate is less than 0.3 mm, it is likely to be damaged during processing or due to pressure during imprinting.

The nanoimprint substrate can have a platform type structure.

(resist coating step)

A method of arranging a predetermined amount of droplets at a predetermined position, such as an inkjet method and a dispensing method, to coat a nanoimprint substrate with a resist is applied. When the droplets of the resist are arranged on the nanoimprint substrate, an ink jet printer or dispenser can be used depending on the desired amount of droplets. For example, in the case where the amount of droplets is less than 100 nanoliters (nl), the ink jet printer can be selected, and in the case where the amount of droplets is 100 nanoliters or more, the dispenser can be selected.

Examples of the ink jet head that discharges the resist from the nozzle include piezoelectric type, thermal type, and electrostatic type. In these examples, a piezoelectric ink jet head is preferred in which the amount of droplets (the amount of resist in each of the aligned droplets) and the discharge speed are adjustable. The amount of droplets and the discharge rate are set and adjusted before the resist droplets are arranged on the nanoimprint substrate. For example, it is preferable to adjust the amount of droplets to be large in a region where the volume of the concave-convex pattern of the mold is large, and to adjust to be small in a region where the volume of the concave-convex pattern of the mold is small. Such adjustment is controlled as appropriate depending on the amount of droplet discharge (the amount of resist in each discharged droplet). Specifically, in the case where the amount of droplets is set to 5 picolitres (pl), the inkjet head whose droplet discharge amount is 1 picoliter is controlled so that the droplets are discharged at the same position five times. In the present invention, the amount of droplets ranges from 1 picoliter to 10 picolitres Inside. The amount of droplets is obtained by measuring the three-dimensional shape of the droplets arranged on the substrate under the same conditions with a confocal microscope or the like and by calculating the volume of the droplets according to the shape thereof.

After adjusting the amount of droplets as described above, the droplets are arranged on the nanoimprint substrate according to a predetermined droplet arrangement pattern.

In the case of applying a spin coating method or a dip coating method, the resist is diluted with a solvent to achieve a predetermined thickness. In the case of the spin coating method, the rotation speed is controlled, and in the case of the dip coating method, the pulling speed is controlled to form a uniform coating film on the nanoimprint substrate.

(imprint step)

The residual gas is reduced by depressurizing the atmosphere between the mold and the substrate or by vacuuming the atmosphere between the mold and the substrate before contacting the mold with the resist. However, the resist may volatilize prior to curing in a vacuum environment, resulting in difficulty in maintaining a uniform film thickness. Therefore, it is preferable to reduce the amount of residual gas by making the atmosphere between the substrate and the mold into an atmosphere or a decompression atmosphere. The crucible passes through the quartz substrate, so the amount of residual gas (氦) will gradually decrease. Since it takes time to pass through the quartz substrate, it is better to use a decompressed atmosphere. The pressure of the atmosphere under reduced pressure is preferably in the range of 1 kPa to 90 kPa, and more preferably in the range of 1 kPa to 10 kPa.

After the mold is aligned with the substrate coated with the resist to have a predetermined positional relationship, they are brought into contact with each other. Alignment marks are preferably used for the alignment operation. The alignment marks are formed by a concavo-convex pattern which can be detected by an optical microscope or by a Moire interference technique. The positioning accuracy is preferably 10 micrometers or less, more preferably 1 micrometer or more. Small, and the best is 100 nm or less.

The mold is pressed against the substrate at a pressure in the range of 100 kilopascals (kPa) to 10 megapascals (MPa). When the pressure is high, the resist flow is promoted, the residual gas is compressed, the residual gas is dissolved in the resist, and the crucible is promoted to pass through the quartz substrate. However, if the pressure is too high, the mold and the substrate may be damaged if a foreign object is inserted between the mold and the substrate when the mold contacts the substrate. Therefore, the pressure is preferably in the range of 100 kPa to 10 MPa, more preferably in the range of 100 kPa to 5 MPa, and most preferably in the range of 100 kPa to 1 MPa. The reason why the lower limit of the pressure is set to 100 kPa is that when the embossing is performed in the atmosphere, the gap between the mold and the substrate is filled with liquid, and the gap between the mold and the substrate is from atmospheric pressure (about 101 kPa). ) Pressurization.

After the mold is pressed against the nanoimprint substrate and a resist film is formed, the mold is separated from the resist film. As an example of the separation method, the outer edge portion of one of the mold and the nanoimprint substrate may be held while the back of the other of the mold and the nanoimprint substrate is held by vacuum suction, and the outer edge is provided The holding portion or the holding portion of the back side relatively moves in a direction opposite to the pressing direction.

(repeated demoulding treatment)

In the nanoimprinting, the release agent 6 on the surface of the mold 1 is worn out when the imprinting operation is repeated. Therefore, it is preferred to subject the mold to a mold release treatment after each predetermined number of pressing steps or according to the degree of wear of the release layer (reduction in the coating rate of the release agent). The release treatment after the embossing operation is the same as the release treatment described above, which is performed at the time of manufacturing the mold 1. In the portion where the release agent 6 on the surface of the mold 1 is thinned, and in particular, in the mold main In the exposed portion of the body 12, there is a large amount of adsorbed water 2. In the case where the release agent 6 is diffused by the meniscus of the adsorbed water 2, the release agent 6 is concentrated at the portion where the release agent 6 is thinned. Thereby, the release layer 14 can be repaired while maintaining the thickness distribution of the release layer 14 from the top surface St of the convex portion to the bottom surface Sb of the concave portion.

[Method of Manufacturing Patterned Substrate]

Next, an embodiment of a method of manufacturing the patterned substrate of the present invention will be described. This embodiment applies the nanoimprint method described above to fabricate a patterned substrate.

First, a resist film formed with a pattern by the nanoimprint method described above is formed on the surface of the substrate to be processed. Subsequently, etching is performed using the resist film on which the pattern is formed as a mask to form a concavo-convex pattern corresponding to the concavo-convex pattern of the resist film. Thereby, a patterned substrate (replica) having a predetermined pattern is obtained.

In the case where the substrate to be treated has a layered structure and a mask layer is included on the surface thereof, a pattern formed by the nanoimprint method described above is formed on the surface of the substrate to be treated having the mask layer. Resist film. Next, dry etching is performed using a resist film as a mask to form a concavo-convex pattern corresponding to the concavo-convex pattern of the resist film in the mask layer. Thereafter, dry etching is additionally performed using the mask layer as an etch stop layer to form a concavo-convex pattern in the substrate. Thereby, a patterned substrate having a predetermined pattern is obtained.

The dry etching method is not particularly limited as long as it can form a concavo-convex pattern in the substrate, and can be selected according to the intended use. Examples of dry etching methods that can be applied include: ion milling; RIE (reactive ion etching); sputtering etching; In these methods, the ion milling method The RIE method is particularly preferred.

Ion milling is also known as ion beam etching. In ion milling, an inert gas such as argon is introduced into the ion source to generate ions. The generated ions are accelerated via the gate and collide with the sample substrate for etching. Examples of ion sources include: Kauffman type ion sources; high frequency ion sources; electron bombardment ion sources; dual triode ion sources; Freeman ion sources; and electron cyclotron resonance (Electron Cyclotron Resonan) -ce, ECR) ion source.

During the ion beam etching, argon gas can be used as the processing gas. During the RIE, a fluorine series gas or a chlorine series gas may be used as an etchant.

As described above, the method of manufacturing the patterned substrate of the present invention is carried out using the mold of the present invention which has high mold release property over the entire surface of the concave-convex pattern. Therefore, it is possible to perform highly accurate processing in the manufacture of a patterned substrate using nanoimprint.

Further, the method for producing a patterned substrate of the present invention is dry-etched using a resist film having a high-contrast concave-convex pattern formed by the nanoimprint method described above as a mask. Therefore, the substrate can be processed with high precision and high yield.

[Example]

Examples of the invention and comparative examples will be described below.

<Example 1> (manufacturing of molds)

First, a Si substrate is coated with a resist liquid by spin coating to form a resist layer having polyhydroxystyrene (polyhydroxy styrene) The styrene, PHS series of chemically amplified resists are the main components. Thereafter, an electron beam (adjusted according to a line pattern having a line width of 30 nm and a pitch of 60 nm) was irradiated onto the resist layer while the Si substrate was scanned on the XY stage so that the entire resist layer was 0.5. A linear concave-convex pattern on the square millimeter range is exposed.

Thereafter, the photoresist layer is subjected to development processing, and the exposed portion is removed. Finally, by selective etching using a portion of the resist layer from which the exposure was removed as a mask by RIE, a depth of 60 nm was obtained to obtain a ruthenium mold having a linear concave-convex pattern. The taper angle of the concave and convex pattern is 85 degrees.

The surface of the crucible mold body is cleaned with a UV ozone treatment device to change the properties of the surface of the crucible mold body to be hydrophilic.

(release treatment substrate)

A 0.525 mm thick Si wafer was used as the release treatment substrate. First, the surface of the Si wafer was cleaned with a UV ozone treatment device. Next, a release agent, Opto DSX, manufactured by Daikin Industries KK, was dissolved in a fluorine-based special solvent HD-ZV manufactured by Daikin Industries KK to prepare 0.1. The mold release treatment liquid of the weight percent of the Opto DSX. The Si wafer was immersed in the release treatment liquid for 1 minute, and then pulled up at a constant speed of 5 mm/sec to dip the release agent on the Si wafer. The film thickness of the release agent was 5 nm.

(release method)

The enamel mold body and the Si wafer were placed in a nanoimprinting apparatus. The crucible mold body and the Si wafer were brought into contact with each other under the following conditions: room temperature 25 ° C; and 80% relative humidity. Maintain the contact state for 5 minutes, then separate 矽 Mold body and Si wafer. The release layer is formed by the method described above, and has a thickness distribution of a thickness of 3 nm at the top surface of the convex portion, a thickness of 1 nm at the bottom surface of the concave portion, and a thickness at the side of the convex portion. The top to bottom surface is continuously changed from 3 nm to 1 nm. The crucible mold is obtained by the above steps.

(nano imprinted substrate)

A 0.525 mm thick quartz substrate was used as the substrate. The surface of the quartz substrate was treated with a decane coupling agent KBM-5103 (manufactured by Shin-Etsu Chemical Industries, K.K.) having excellent close contact properties with respect to the resist. KBM-5103 was diluted to 1% by mass using PGMEA and applied to the surface of the substrate by spin coating. Thereafter, the coated substrate was annealed on a hot plate at 150 ° C for 5 minutes to bond the decane coupling agent to the surface of the substrate.

(resist)

A resist containing 48% by weight of Compound A represented by Chemical Formula 1, 48% by weight of Onyx M220, 3% by weight of IRGACURE 379, and 1% by weight of Compound B represented by Chemical Formula 2 was prepared as a resist. .

(resist coating step)

DMP-2831 is used, which is a piezoelectric inkjet printer manufactured by FUJIFILM Dimatix. A DMC-11610, a dedicated 10 picoliter (pl) head, is used as the ink jet head. The ink discharge conditions were set in advance and adjusted so that the amount of the resist per droplet was 10 picoliters. After adjusting the amount of droplets in this manner and adjusting so that the residual film thickness will become 10 nm, the droplets are arranged on the substrate according to a predetermined droplet arrangement pattern. on.

(imprint step)

The tantalum mold and the quartz substrate are brought close to each other such that the gap therebetween is 0.1 mm or less, and the back surface of the quartz substrate is positioned such that the position of the alignment mark on the quartz substrate matches the position of the alignment mark on the mold. . The gap between the crucible mold and the quartz substrate was filled with a gas containing 99% by volume or more of helium gas. Subsequently, the pressure is reduced to 20 kPa or less. The mold was brought into contact with the resist droplets under reduced pressure helium. After the contact, a pressure of 1 MPa was applied for one minute, and an irradiation dose of 300 mJ/cm 2 of ultraviolet light having a wavelength of 360 nm was applied to cure the resist. Thereafter, the back surface of the quartz substrate and the crucible mold were held by suction. Subsequently, the quartz substrate or the crucible mold is relatively moved in a direction opposite to the pressing direction to separate the crucible mold.

(矽 mold copy manufacturing steps)

Dry etching is performed using a resist film to which a concavo-convex pattern has been transferred as a mask as described below. Thereby, the convex portion and the concave shape based on the concave-convex pattern of the resist film are formed on the quartz substrate. First, the residual film present in the recess of the pattern is removed by oxygen plasma etching to expose the quartz substrate in the recess of the pattern. At this time, conditions are set such that the amount of etching can remove the thickest residual film in the concave-convex pattern region. Next, RIE using a fluorine-based gas was applied to the quartz substrate using the convex portion of the pattern as a mask. The RIE conditions were set so that the etching depth was 60 nm. Finally, the residue of the relief of the pattern is removed by oxygen plasma etching. Therefore, a replica mold having a predetermined concave-convex pattern is obtained.

A quartz mold, which is a replica of the tantalum mold, is produced by the above-described replication manufacturing step.

<Example 2>

The same steps as those performed in Example 1 were carried out, but the release treatment was carried out using a chemical vapor deposition method as described below.

The mold release agent is heated to be vaporized by decompressing the inside of the container having the mold inside to 10 kPa or less, and the gas containing the release agent is introduced into the container while controlling the flow rate and exposing the mold surface to the inclusion. The release treatment of the chemical vapor deposition method is performed in the atmosphere of the gaseous release agent. Forming a release layer on the surface of the mold body by the method described above, the thickness distribution of which is 3 nm at the top surface of the convex portion, the thickness at the bottom surface of the concave portion is 1 nm, and the convex portion The thickness at the side of the surface varies continuously from 3 nm to 1 nm from the top surface to the bottom surface.

<Example 3>

Perform the same steps as those performed in Example 1, but with an electron beam (line pattern according to a line width of 30 nm and a pitch of 60 nm and a line pattern with a line width of 300 nm and a pitch of 600 nm) The light is irradiated on the resist layer while the Si substrate is scanned on the XY stage to expose the linear concave-convex pattern having different widths in the recesses of the resist layer in the range of 5 mm 2 .

<Comparative Example 1>

A mold having a release layer only on the convex portion is produced. The other steps were the same as those performed in Example 1, except for the demolding step.

(release method)

The crucible mold body and the release treatment substrate are placed in a nanoimprinting apparatus. The crucible mold body and the release-treated substrate were brought into contact with each other under the following conditions: room temperature 25 ° C; and 20% relative humidity. The contact state was maintained for 1 minute, and then the crucible mold body and the release substrate were separated. The release of the release agent through the meniscus is suppressed by low humidity and short contact time. A release layer is formed on the surface of the crucible mold body by the method described above, and the thickness distribution is such that the thickness at the top surface of the convex portion is 3 nm, the thickness at the bottom surface of the concave portion is 0 nm, and convex The thickness at the side of the place is less than 3 nm.

<Comparative Example 2>

The same steps as those performed in Example 1 were carried out, but the demolding treatment was carried out using a dip coating method as described below.

The release treatment by the dip coating method was carried out by immersing the ruthenium mold main body in a solution in which the release agent was dissolved for 1 hour at a concentration of 0.1% by weight. Forming a release layer on the surface of the crucible mold body by the method described above, the thickness distribution of which is 1 nm at the top surface of the convex portion, 1 nm at the bottom surface of the concave portion, and convexity The thickness at the side of the section is uniform.

<Comparative Example 3>

Perform the same steps as those performed in Example 2, but with an electron beam (line pattern according to a line width of 30 nm and a pitch of 60 nm and a line pattern with a line width of 300 nm and a pitch of 600 nm) The light is irradiated on the resist layer while the Si substrate is scanned on the XY stage to expose the linear concave-convex pattern having different widths in the recesses of the resist layer in the range of 5 mm 2 . Note that the release layer is adjusted to have a line width of 30 nm and The desired thickness is in the region of the line pattern having a pitch of 60 nm. That is, a portion of the line pattern having a line width of 30 nm and a pitch of 60 nm is formed to form a release layer such that the thickness of the top surface of the protrusion is 3 nm, and the bottom surface of the recess is The thickness is 1 nm, and the thickness at the side of the convex portion continuously changes from 3 nm to 1 nm from the top surface to the bottom surface. Therefore, the release layer in the line pattern region having a line width of 300 nm and a pitch of 600 nm becomes no thickness distribution, wherein the thickness at the top surface of the protrusion is 2 nm, and the thickness at the bottom surface of the recess is It is 2 nm, and the thickness at the side of the protrusion is about 2 nm.

<Evaluation method>

Specific evaluation methods regarding the pattern formability of the resist pattern, the durability of the mold, the number of defects increased at the time of the reverse mold release treatment, and the productivity of the nanoimprint operation, and the evaluation results will be described hereinafter.

The pattern formability of the resist pattern was evaluated by cutting the resist pattern formed by the nanoimprint operation in the vertical direction and measuring the cross-sectional shape thereof by AFM and/or scanning electron microscopy. The inclination angle of the convex portion in the concave-convex pattern region having a line width of 30 nm and a pitch of 60 nm was used as an index. In addition, with respect to Example 3 and Comparative Example 3 only, the evaluation of the depth uniformity was performed using the difference of the depth average values in the pattern regions having different line widths and pitches. The tilt angles and differences of the examples and comparative examples are shown in Table 1.

The durability of the mold was evaluated by observing the surface of the mold with an optical microscope, a scanning electron microscope, and an atomic force microscope after performing 100 nanoimprint operations. The number of foreign objects adhered to the surface is used as the durability index. When the evaluation results were compared, in the case where the number of foreign objects adhered to the mold of Example 1 was designated as 100, the relative values of the numbers of the examples and the comparative examples were calculated. The number of adhesions of the respective examples and comparative examples is shown in Table 2.

The number of defects added to the reverse mold release treatment by performing the mold release treatment again after performing 100 nanoimprint operations and observing the surface of the mold with an optical microscope, a scanning electron microscope, and an atomic force microscope before and after the mold release treatment to evaluate. The increase in the number of substances adhered to the surface (the increase in the number of defects) was used as the evaluation index. When the evaluation results were compared, in the case where the increase in the number of defects in the mold of Example 1 was set to 100, the relative values from which the number of defects of the example and the comparative example were increased were calculated. The increase in the number of defects of each of the examples and the comparative examples is shown in Table 3.

The productivity of the nanoimprint operation was evaluated using the total amount of time required for the release treatment (including transporting the mold from the release treatment device to the nanoimprinting device and placing the mold) as an index. When the evaluation results were compared, in the case where the total time of the mold of Example 1 was designated as 100, the relative values of the total time of the example and the comparative example were calculated. The total time of each example and comparative examples is as shown in Table 4.

<evaluation result>

The evaluation results related to Example 2 will be discussed. In the mold release treatment using the chemical vapor deposition method, it is necessary to use a dedicated vapor deposition apparatus different from the nano imprint apparatus. Therefore, its productivity is slightly worse than that of Example 1, but the decrease in productivity is within an acceptable range. The pattern formability of the resist pattern is comparable to that of Example 1, because the thickness of the release layer can be controlled so that the thickness at the bottom surface of the recess can be controlled. The durability of the mold and the number of defects added during the repeated demolding treatment were comparable to those of Example 1.

The evaluation results related to Example 3 will be discussed. The depth of the recess is slightly waved The pattern formability is slightly deteriorated because the pattern on the enamel mold has recesses having different widths. However, the deterioration of pattern formability is within an acceptable range. The durability of the mold, the number of defects added during the repeated demolding treatment, and the productivity of the nanoimprint were comparable to those of Example 1.

The evaluation results related to Comparative Example 1 will be discussed. The pattern formability was inferior to that of Example 1, because the release agent was present only on the top surface of the convex portion. Further, the number of embossing defects caused by clogging, defects in the resist pattern, peeling, and the like were more than that of Example 1, because the mold release agent was not present on the bottom surface of the recess. The increase in the number of defects during the reverse mold release treatment was comparable to that of Example 1, and the productivity of the nanoimprint was greater than that of Example 1.

The evaluation results related to Comparative Example 2 will be discussed. The pattern formability was inferior to that of Example 1, because the release treatment using the dip coating method uniformly applied the entire uneven pattern with the release agent. In addition, the number of defects at the time of the reverse mold release treatment was increased more than that of Example 1, because the foreign matter adhered to the back side and the side surface of the mold in the nanoimprinting apparatus or during transportation adhered to the surface during immersion. In addition, the productivity of nanoimprinting is inferior to that of Example 1, because a dedicated impregnation apparatus must be utilized outside of the nanoimprinting apparatus. The durability of the mold was comparable to that of Example 1.

The evaluation results related to Comparative Example 3 will be discussed. In the demolding process using the chemical vapor deposition method, if there is a pattern having a recess having a different width on the main body of the crucible, the thickness of the release layer at the bottom of the recess will be greater in the recess having a larger width. Big. Therefore, the uniformity of the pattern depth is deteriorated, and the pattern formability is inferior to that of Example 3. When the width of the line of the recess is large and/or the aspect is relatively small (with a line width of about 100 nm and an aspect ratio of 1) For the boundary), it is difficult to impart a certain thickness distribution to the release layer on the side. In addition, in the mold release treatment using the chemical vapor deposition method, a dedicated vapor deposition apparatus must be utilized outside the nanoimprint apparatus. Therefore, the productivity of nanoimprinting is slightly worse than that of Example 1. However, the reduction in productivity of nanoimprinting is within an acceptable range. The durability of the mold and the number of defects added during the repeated demolding treatment were comparable to those of Example 1.

Table 5 summarizes the evaluation results associated with the examples and comparative examples.

The description of Table 5 is as follows.

In the column relating to the formability of the resist pattern, the case where the inclination angle of the convex portion is more than 85 degrees (this is the taper angle at the time of manufacturing the mold main body) is evaluated as "good", and the angle is A situation of 85 degrees or lower was evaluated as "poor". However, if the difference in the average value of the depth in the depth uniformity evaluation is 1 nm or more, the formability of the resist pattern is evaluated as "poor" even if the inclination angle of the convex portion is more than 85 degrees.

In the column related to the durability of the mold, the case where the number of foreign objects is less than 150 is evaluated as "good", and the number of cases of 150 or more is evaluated. Estimated as "poor".

In the column relating to an increase in the number of defects at the time of the reverse mold release treatment, the case where the increase in the number of defects is 150 or less is judged as the small increase in the number of defects, and is evaluated as "good", and the number of defects is increased more. The situation at 150 was evaluated as "poor".

Among the items related to the productivity of nanoimprinting, the case where the total time is 150 or less is evaluated as "good", and the case where the total time is more than 150 is evaluated as "poor".

As can be understood from Table 5, the mold of the present invention, that is, the molds of Examples 1 to 3, the formability of the resist pattern, the durability of the mold, the increase in the number of defects during the reverse mold release treatment, and the nano pressure. Printed productivity shows superior performance. From the results associated with Comparative Example 3, it can be understood that even if chemical vapor deposition is applied (promising results are produced in Example 2), formability in the resist pattern when the mold contains patterns of different line widths and pitches There are also problems with the depth uniformity of specific words. As indicated by the results of the evaluation associated with Example 3, the uniformity of depth is improved and all evaluation items exhibit superior performance. Compared with Example 1 to Example 3, none of Comparative Example 1 to Comparative Example 3 was comparable or higher in terms of all evaluation items. The above results confirm the superiority of the present invention.

1‧‧‧Mold

2‧‧‧Adsorption water

5‧‧‧Release treatment substrate

6‧‧‧Release

6a‧‧‧Release

12‧‧‧Mold main body

13‧‧‧ concave pattern

14‧‧‧ release layer

H‧‧‧The height of the protrusion from the bottom of the recess/depth of the recess

Sb‧‧‧ bottom

Ss‧‧‧ side

St‧‧‧ top

W1‧‧‧Width of the convexity

Distance between W2‧‧‧ convex

Fig. 1 is a schematic cross-sectional view illustrating a structure of a mold.

Fig. 2 is a schematic cross-sectional view illustrating one step of a method of manufacturing the mold.

Figure 3 is a schematic illustration of one step of the method of manufacturing the mold Cutaway view.

Fig. 4 is a schematic cross-sectional view illustrating one step of a method of manufacturing the mold.

Fig. 5 is a schematic cross-sectional view illustrating one step of a method of manufacturing the mold.

Fig. 6 is a schematic cross-sectional view illustrating one step of a method of manufacturing the mold.

2‧‧‧Adsorption water

5‧‧‧Release treatment substrate

6‧‧‧Release

6a‧‧‧Release

12‧‧‧Mold main body

Claims (11)

A mold release treatment method, which is suitable for forming a release layer on the surface of a mold body having a fine concave and convex pattern on a surface, the method comprising: preparing a release treatment substrate coated with a release agent; The mold body having adsorbed water on the surface and the mold release substrate are brought close to each other until a contact state, wherein an upper portion of the convex portion of the concave-convex pattern is in contact with the release agent; and the contact state is maintained until the formation The release layer is such that the thickness distribution of the release layer is such that the thickness of the release layer at the side of the relief pattern is from the top of the protrusion due to diffusion of the release agent into the adsorption water The surface is thinned toward the bottom surface of the recess; and the mold body and the mold release substrate are separated from each other such that the upper portion of the protrusion is separated from the release agent on the release treatment substrate. The mold release treatment method according to claim 1, wherein the mold release treatment method is performed inside a nanoimprinting apparatus. A method of manufacturing a nanoimprinting mold having a mold body having a fine concavo-convex pattern on a surface and a release layer on the surface of the mold main body, the method characterized by including Preparing a release-treated substrate coated with a release agent; bringing the mold body having adsorbed water on the surface and the release-treated substrate close to each other until a contact state, wherein the concave-convex pattern The upper portion of the convex portion is in contact with the release agent; maintaining the contact state until the release layer is formed such that the thickness distribution of the release layer is the thickness of the release layer at the side of the concave-convex pattern Thinning from a top surface of the convex portion toward a bottom surface of the concave portion due to diffusion of the release agent into the adsorbed water; and separating the mold main body and the mold release treatment substrate from each other such that the convex portion The upper portion is separated from the release agent on the release treated substrate. The method for producing a nanoimprinting mold according to the third aspect of the invention, wherein the method for producing the nanoimprinting mold is performed inside a nanoimprinting apparatus. A nano imprinting mold comprising: a mold main body having a fine concavo-convex pattern on a surface; and a release layer on the surface of the mold main body; wherein a thickness distribution of the release layer is The thickness of the release layer at the side of the concave-convex pattern is thinned from the top surface of the convex portion toward the bottom surface of the concave portion. The nanoimprinting mold according to claim 5, wherein the thickness distribution of the release layer is such that the thickness at the side surface is as thick as the thickness at the top surface. Reduced to a thickness as thick as the thickness at the bottom surface. The nano imprinting mold according to claim 5 or 6, wherein: The thickness distribution of the release layer is such that the thickness at the top surface is in the range of 1 nm to 5 nm, and the thickness at the bottom surface is in the range of 0.1 nm to 1 nm and is The thickness at the top surface is 70% or less. A nanoimprinting method, comprising: using a mold as described in claim 5; coating a nanoimprint substrate with a resist; pressing the mold on the nanoimprint substrate Coating the surface of the resist; and separating the mold from the nanoimprint substrate. The nanoimprint method according to claim 8, wherein the mold is subjected to a mold release treatment after a predetermined number of pressing steps or according to a degree of wear of the release layer, The demolding treatment includes: preparing a release-treated substrate coated with a release agent; and bringing the mold main body having adsorbed water on the surface and the release-treated substrate to each other until a contact state, wherein the concave-convex pattern is convex The upper portion is in contact with the release agent; maintaining the contact state until the release layer is formed such that the thickness distribution of the release layer is the thickness of the release layer at the side of the concave-convex pattern Dissolving the release agent into the adsorbed water and thinning from a top surface of the convex portion toward a bottom surface of the concave portion; and separating the mold main body and the mold release treatment substrate from each other such that the convex portion The upper portion is separated from the release agent on the release treated substrate. The nanoimprint method according to claim 9, wherein the step of pressing the mold against the nanoimprint substrate and the step of performing the mold release treatment are both The meter imprinting device is executed inside. A method of manufacturing a patterned substrate, comprising: forming a resist film having a textured pattern on a substrate to be processed by a nanoimprint method as described in claim 8; and using The resist film is etched as a mask to form a concavo-convex pattern corresponding to the concavo-convex pattern transferred onto the resist film.