JP2011222647A - Pattern forming method and pattern substrate manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for productively forming a high-accuracy pattern having a good etching resistance by an imprinting method.SOLUTION: In the method, a resist composition 20 comprising a polymeric compound 21, a polymerization initiator I activated by light or an electron beam L1 and a polymeric surfactant 22 containing fluorine is discretely arranged on a substrate 10 as a plurality of droplets to form a resist layer 20m. A concavoconvex surface of a mold 30 having a predetermined concavoconvex pattern thereon is pushed with pressure to the resist layer 20m and also light or the electron beam L1 is irradiated to the resist layer 20m so as to harden the resist layer 20m, thereby separating the mold 30 from the resit layer 40.

Description

  The present invention relates to a pattern forming method using an imprint method and a method of manufacturing a pattern substrate using a pattern formed by the method.

  In the formation of nano-order patterns for patterned media and semiconductor devices, the optical imprint method has attracted attention. The optical imprint method is a method of forming a reversed pattern on an object to be processed by a transfer method based on a fine pattern on a mold (mold), and a mold having a predetermined pattern to be transferred formed on the surface. This is a technique for transferring a pattern by applying pressure to a liquid resist material arranged on a substrate and then curing the resist material with light.

  The optical imprint method is expected as a next-generation manufacturing technology for microfabrication because pattern formation can be performed easily and at low cost by using a mold having a desired pattern.

  In the optical imprinting method, there is a problem that the accuracy of a pattern obtained by causing unevenness in the thickness of the remaining film between the concave portion after imprinting and the substrate depends on the pattern arrangement and the substrate shape. In order to solve such a problem, a method has been proposed in which a resist is arranged in a specific pattern of discrete droplets according to the pattern arrangement, the concave volume, and the substrate shape (Patent Documents 1 to 3).

  In addition, as a method for easily placing droplets on a substrate with relatively high accuracy, droplets are applied by an inkjet method. In the ink jet method, good discharge properties and discharge stability are important, and it is known that these are influenced by the control of physical properties of the discharge liquid.

  For example, if the liquid physical properties cannot be controlled and the liquid physical properties greatly deviate from the recommended range, abnormalities occur in the droplet volume control and the discharge direction control. A problem arises in that droplets other than the droplets are ejected and landed, making it impossible to form an accurate pattern. In addition, ejection stability cannot be ensured due to degradation of ejection accuracy due to nozzle contamination.

  In addition to the liquid physical properties related to the discharge properties, the resist material has a mold release property when removing the mold after curing, an etching resistance in a lithography process after pattern formation, a pattern shape such as rectangularity and roughness, Thinness of the remaining film thickness and in-plane uniformity are required.

  Patent Document 4 discloses an imprint resist containing a fluororesin as a main component, and ensures a good release property by using the fluororesin as a main component. However, the viscosity of the resist is higher than that suitable for inkjet, and it is difficult to arrange the resist in a desired pattern with high productivity. Furthermore, since the fluorination rate is high, the etching resistance in the post-imprinting process cannot be sufficiently obtained in the nano-order pattern formation.

  In Patent Document 5, a resist composition containing a surfactant is used as a discharge liquid, and in addition, in order to improve the wettability and releasability of the resist material with respect to the mold, locations on the mold surface corresponding to the droplet arrangement A technique for adhering a large amount of a surfactant to the surface has been proposed. Patent Document 6 discloses that a surfactant is used in a silicon-containing resist composition in order to improve releasability.

US Patent Application Publication No. 2005/0273012 US Patent Application Publication No. 2005/0106321 US Patent Application Publication No. 2009/0148619 US Patent Application Publication No. 2006/0036051 US Patent Application Publication No. 2009/01366549 US Patent Application Publication No. 2006/0036051

  However, the technique described in Patent Document 5 is difficult to apply to patterns of several tens of nanometer size or less because the pattern shape accuracy decreases due to accumulation of surfactant on the mold surface.

  Further, in the technique of Patent Document 6, the surfactant contained in the resist is likely to adhere to the mold surface. Further, as shown in FIG. 3, the arrangement pattern of the resist composition on the substrate and the surfactant The surfactant is unevenly distributed corresponding to the material properties such as hydrophilicity / hydrophobicity and viscosity and the compatibility with the resist composition, and the resist at the unevenly distributed portion (shaded portions in FIGS. 3B and 3C) is not cured. There is a problem that defects occur. In any of the patent documents, there is a problem in mass productivity because the quality deterioration rate of the mold is increased by the surfactant.

  The present invention has been made in view of the above circumstances, and provides a pattern formation method that enables high-precision patterning even in nano-order pattern formation in the pattern formation by the imprint method, and is excellent in mass productivity and etching resistance. It is intended to do.

  Another object of the present invention is to manufacture a patterned substrate with high precision by processing the substrate by lithography using the mask formed by the pattern forming method.

  In the pattern forming method of the present invention, a resist composition comprising a polymerizable compound, a polymerization initiator activated by light or an electron beam, and a polymerizable surfactant containing fluorine is formed as a plurality of droplets on a substrate. A resist layer formed in a discrete manner is formed, the surface of the mold having a predetermined uneven pattern on the surface is pressed against the resist layer, and the resist layer is irradiated with the light or the electron beam. Is cured, and the mold is peeled off from the resist layer.

Here, the “fluorine-containing polymerizable surfactant” has a function as a surfactant, and the “fluorine-containing polymerizable surfactant” and the “polymerizable compound” are different substances. “Polymerizable compound” may contain fluorine, but in a droplet, it is a fluorine content at which uneven distribution on the surface of the droplet is sufficiently less than “polymerizable surfactant containing fluorine”. Or a structure that does not substantially contain a fluoroalkyl group or a fluoroalkyl ether group in the structure. As such fluorine content, the fluorine content in the compound represented by the following formula (C1) is 5% or less.
Formula (C1)

  The content of the polymerizable surfactant in the resist composition is preferably 5% by mass or less.

  In the pattern forming method of the present invention, the polymerizable surfactant has a plurality of at least one fluorine-containing group selected from a fluoroalkyl group and a fluoroalkyl ether group in the monomer of the polymerizable surfactant. In addition, it is preferable to use a fluorine-containing polymerizable compound in which at least two of the plurality of fluorine-containing groups are separated by a linking group having 2 or more carbon atoms. More preferably, at least two of the fluorine-containing groups are fluoroalkyl groups having 2 or more carbon atoms. Furthermore, it is preferable that at least two of the fluorine-containing groups are trifluoromethyl groups.

  As the polymerizable compound, it is preferable to use a polyfunctional monomer that is cross-linked by polymerization to become a polymer having a three-dimensional structure, and the polyfunctional monomer includes at least one divalent or trivalent aroma. It is preferable to have a group. Moreover, it is also preferable to use the monomer which has a cyano group as said polymeric compound.

  Here, the “polyfunctional monomer” means a monomer having a plurality of ethylenically unsaturated double bonds.

  In the pattern forming method of the present invention, before disposing the resist layer on the substrate, an interfacial binder that bonds the surface and the resist layer to each other on the surface on which the resist layer is disposed; Alternatively, it is preferable to apply an adhesive.

  The patterned substrate manufacturing method of the present invention uses the resist layer patterned on the substrate by the pattern forming method of the present invention as a mask, and the concavo-convex pattern based on the pattern of the resist layer on the substrate surface by lithography. A pattern is formed.

  In the pattern forming method of the present invention, a resist composition containing a polymerizable compound, a polymerization initiator activated by light or an electron beam, and a polymerizable surfactant containing fluorine is formed as a plurality of droplets on a substrate. A resist layer formed by discrete arrangement is formed. Since such a resist layer has a low fluorine content in the resist composition, the viscosity of the resist composition and the etching resistance of the resist material after curing are suitably maintained, and a polymerizable fluorine-containing surfactant is included. Thus, the mold-releasing property can be improved by the fluorine-containing portion without promoting pattern formation failure or deterioration of the template due to uneven distribution, adhesion, and accumulation of the surfactant.

  Therefore, according to the present invention, in the pattern formation by the imprint method, highly accurate patterning is possible even in the nano-order pattern formation, and the pattern formation excellent in mass productivity and etching resistance can be performed.

  Further, a patterned substrate with high accuracy can be manufactured by processing the substrate by lithography using the resist pattern made by the pattern forming method of the present invention as a mask.

(A)-(e) is sectional drawing which shows the manufacturing process of the pattern formation method and pattern board | substrate of this invention typically Sectional drawing which shows typically the structure of the droplet of a resist composition (A)-(c) is the figure which showed typically the state of the resist composition and resist layer on a board | substrate in the manufacture process at the time of using the resist composition containing non-polymerizable surfactant.

"Pattern formation method"
With reference to FIG. 1, the pattern formation method and pattern substrate manufacturing method of one Embodiment concerning this invention are demonstrated. 1A to 1E are cross-sectional views schematically showing the pattern forming method of the present invention. In order to facilitate visual recognition, the scale of each part is appropriately changed and shown.

(Resist application process)
First, a substrate 10 is prepared (FIG. 1A). On the substrate 10, a polymerizable compound 21, a polymerization initiator I activated by light or electron beam, a polymerizable surfactant 22 containing fluorine, The resist composition 20 containing is discretely arranged as a plurality of droplets to form the resist layer 20m. (FIG. 1 (b)).

  As the substrate 10, one having good surface smoothness is preferable, but not particularly limited. In the pattern formation method of this embodiment, since the resist layer 20m is cured by light or an electron beam L1 (hereinafter referred to as light L1), either the substrate 10 or a mold (mold) 30 used in a subsequent process is used. The light L1 needs to be translucent. Here, having translucency means having a transmittance capable of reaching the resist layer 20m with an amount of light L1 that can cure the resist 20. If the transmittance of the light L1 is 1% or more, the resist 20 can be cured, but is preferably 10% or more, and more preferably 50% or more.

Examples of the substrate 10 include aluminum, glass, silicon, quartz, and a SiO ₂ / Si substrate formed by forming a thermal oxide film on the silicon surface. These board | substrate materials may be used individually by 1 type, and may use 2 or more types together.

  Further, it is preferable that the pattern forming surface 10S of the substrate 10 is subjected to a surface treatment for bonding and adhering the substrate surface 10S and the resist composition 20 before the droplets of the resist composition 20 are disposed. As such surface treatment, a coupling agent having a first functional group having a binding property to the substrate surface and a second functional group having a binding property to the resist layer 20m is formed on the substrate as an interface binder. The process to do is mentioned.

  The first functional group is not particularly limited as long as it can be bonded to the surface of the substrate, and can be appropriately selected from known ones according to the purpose. For example, the first functional group can be cross-linked with an alkoxysilane moiety or an OH group. A carboxylic acid anhydride moiety having halogen, a halogenated moiety and the like.

  The second functional group is not particularly limited as long as it can be bonded to the resist layer 20m (resist composition 20), and the resist can be bonded by a bond such as a covalent bond, a hydrogen bond, an ionic bond, or a van der Waals bond. It can be appropriately selected according to the composition of the resist composition from among known ones that are bonded to the layer 20m.

  The interface binder is preferably one that strengthens the bond between the substrate 10 and the resist layer 20m, but does not deteriorate the removability of the resist layer residue after processing the substrate by etching or the like. Therefore, it is preferable to use an interface binder that can be removed by any of oxygen plasma treatment, oxygen ashing treatment, and UV ozone treatment after substrate processing.

  Examples of such interfacial binders include silane coupling agents and carboxylic acid anhydrides. The method for forming the interface binder is not particularly limited, but a liquid phase method such as spin coating, spray coating, dip coating, or dipping method, and a vapor phase method such as vapor deposition can be appropriately selected.

  In addition, a layer of another material (hardly-etching material layer such as metal) can be provided as a mask layer between the substrate surface 10S and the resist layer 20 (or interface binder). This makes it possible to widen the processing margin by appropriately selecting the reactivity between the reactive gas system in the etching process, which is a subsequent process, and the resist, the substrate to be processed, and the mask layer installed. A quality processed substrate can be produced.

  The arrangement of the droplets 20 is preferably adjusted according to the pattern shape to be formed, the uneven density, the recessed volume, and the wetting and spreading characteristics. By performing such adjustment, it is possible to suppress pattern deficiency, air contamination, and unevenness in the thickness (residual film thickness) between the resist layer recess and the substrate after pattern formation during the press-contact of the mold in the next step.

  If the above adjustment is possible, the method for arranging the droplets is not particularly limited, and examples thereof include a printing method and an ink jet method. The arrangement accuracy is good, and the arrangement position and the amount of resin to be formed can be easily adjusted. Therefore, the inkjet method is preferable.

  The layout pattern is a method of experimentally imprinting using the layout test pattern and designing it based on the relationship between the wetting spread and residual film thickness distribution corresponding to the pattern on the mold and the layout test pattern. Alternatively, an optimal arrangement pattern may be obtained by calculation from the pattern on the mold, the predicted anisotropy of the wetting and spreading of the resist, and their distribution. For example, in the case of a line-shaped pattern, the resist liquid wetting speed using capillary force in the direction along the line on the mold surface is fast and the wetting speed in the direction perpendicular to the line is slow. Drop wetting spread anisotropy can be predicted to some extent.

  As a suitable amount of the droplet 20 to be applied, it is preferable that the thickness of the resist layer 20m after the mold pressure contact is within a range of 5 nm to 200 nm.

  FIG. 2 is a schematic cross-sectional view showing the configuration of the droplet 20. As described above, the droplet 20 made of the resist composition 20 contains the polymerizable compound 21 in a weight content of 50 wt. % Containing 201 as a main component having a ratio greater than%, and a fluorine-containing polymerizable surfactant 22 (hereinafter referred to as fluorine-containing polymerizable surfactant 22) in a weight content of 50 wt. And a polymerization initiator I (not shown) that is activated by the light L1. In addition, 201 and 202 respectively contained fluorine-containing polymerizable surfactant 22 and polymerizable compound 21 at 50 wt. It may contain a small amount of less than%.

  The fluorine-containing compound generally has a property of being unevenly distributed in the interface layer (surface) in the resin layer, and the higher the fluorine substitution rate in the compound, the greater the uneven distribution, which is also shown in FIG. 2 in this embodiment. As described above, the fluorine-containing polymerizable surfactant 202 is present in the droplet 20 so as to cover the surface of the polymerizable compound 201. According to such a configuration, since the surface energy when the droplet 20 is applied onto the substrate is suitably controlled, highly stable ejection can be performed.

  The content of the fluorine-containing polymerizable surfactant 22 in the droplet 20 is 1.0 nm in thickness on the resist layer surface after pattern formation in consideration of mold releasability and pattern quality maintenance in a dry etching process which is a subsequent process. The amount is preferably less than 0.7 nm, more preferably 0.7 nm or less, and even more preferably 0.5 nm or less. In order to obtain such a content, the content is preferably 5% by mass or less in the droplet, more preferably 1% by mass or less. Details of the resist composition 20 will be described later.

(Pattern formation process)
Next, as shown in FIGS. 1C to 1D, after the mold (mold) 30 is pressed against the resist layer 20 m from the upper surface of the substrate and the resist composition 20 is filled in the pattern recesses of the mold 30. The resist layer 20m is cured by irradiating light L1. FIG. 1D shows an example in which the substrate 10 is a substrate 10 having good translucency with respect to the light L1, and the light L1 is irradiated from the substrate side.

  The mold 30 is not particularly limited when the substrate 10 has good translucency with respect to the light L1 as in this embodiment, but as described above, the substrate 10 does not have translucency with respect to the light L1. In this case, since it is necessary to irradiate the light L1 from the mold 30 side, the light L1 needs to be translucent.

  The pattern forming method of the present invention can obtain a more remarkable effect in a region where the pattern size is thin, and can particularly obtain a particularly remarkable effect in a region where the pattern width is 30 nm or less and the pattern aspect ratio is 2 or more.

  As a method for forming the mold 30, it can be formed on the surface of a substrate to be a mold by an existing electron beam drawing method, a transfer method using an exposure machine, a transfer method using imprint, a method combining these, or the like. Based on the formed pattern, pattern processing is performed on the substrate surface by an etching process, and a substrate on which a desired master pattern is processed can be manufactured as a mold.

  The pressure contact of the mold 30 is preferably performed under a helium atmosphere or under reduced pressure. By adopting such a configuration, it is possible to prevent air from entering and remaining between the mold 30 and the resist resin layer 20m, and to avoid formation of a pattern non-formation region due to a gas component.

  When the mold 30 is pressed against the resist layer 20m, the fluorine-containing polymerizable surfactant 22 is unevenly distributed on the surface of the droplet 20 as shown in FIG. The fluorine-containing polymerizable surfactant 22 is unevenly distributed in the interface layer between the mold and the resist. Since the fluorine-containing compound has low adhesion to the mold 30 and has lubricity, in this configuration, the mold 30 can be easily released in the peeling process after the resist layer 20m is cured.

  In order to improve the releasability, the pattern surface of the mold 30 is preferably subjected to a release treatment. As the release treatment, a method of applying a release agent to the pattern surface is simple. As the release agent, a fluorine-containing polymer or a silicone resin is preferable, and a resin having a perfluoropolyether (PFPE) or a perfluoroalkyl chain is particularly preferable.

  The film forming method of the release agent is not particularly limited, and a vapor phase method such as vapor deposition can be used in addition to a liquid phase method such as a dipping method, a spin method, a spray method, and an immersion method.

  As another release treatment method, an inorganic layer having a small interaction with the resist can be provided on the surface to form a release layer. Examples of the inorganic layer include a diamond-like carbon (DLC) layer and a fluorinated DLC layer. Other fluorine-containing inorganic layers may also be used.

  Finally, after the resist layer 20m is cured to form the polymer resist layer 40, the mold 30 is peeled off to form the resist pattern 1 including the resist layer 40 on the substrate 10 (FIG. 1 (e)). ).

  The average thickness of the recesses in the resist layer 40 (average residual film thickness) is 15 nm or less in order to improve the quality of the pattern formed on the substrate after a lithography process such as dry etching, which is a subsequent process. Preferably, it is 10 nm or less, more preferably 5 nm or less. Further, the standard deviation value (σ value) of the remaining film thickness is preferably 5 nm or less, more preferably 3 nm or less, and further preferably 1 nm or less.

  When the remaining film thickness is thick, the resist pattern shape is greatly deteriorated in the step of exposing the substrate surface to be processed by the dry etching process, and it becomes more difficult to obtain a pattern having a desired shape after etching.

  The method for peeling the mold 30 is not particularly limited as long as it is a method that does not easily cause pattern defects, but a method for gradually peeling from the pattern edge portion, a boundary where the mold peels from the resist layer by peeling while pressing from the mold side. A method of peeling by reducing the force applied to the resist layer on the wire (pressure peeling method), and peeling the vicinity of the resist layer in a heated state, thereby attaching the resist layer to the mold surface at the interface between the mold and the resist. Examples thereof include a method (heat-assisted peeling) method in which the adhesion force is reduced, the Young's modulus of the resist layer is lowered, and the brittleness is improved to prevent the breakage due to the deformation and peel. A method combining these methods can also be used.

  In the present invention, since the fluorine-containing polymerizable surfactant 22 is used as the surfactant, the fluidity at the mold interface is reduced as compared with the case where a normal surfactant having no polymerizability is used. Thus, it is preferable to use a heat-assisted peeling method because the resistance force at the time of peeling at room temperature increases.

  When performing heat-assisted peeling, use a peeling device that has a mechanism that controls heating at the mold and substrate chuck, a mechanism that chucks the mold and substrate in the temperature control chamber, and a temperature control mechanism that uses radiant heat. May be. The mold 30 may be peeled off gradually from the peripheral area, or gradually from one end.

  In the “Background Art” section, when the resist composition contains a surfactant, the droplets wet and spread by the pressure contact of the mold have a surfactant corresponding to the arrangement pattern of the resist composition on the substrate. It has been described that the resist is unevenly distributed, and the resist at the unevenly distributed portion is not cured and a pattern defect occurs. FIG. 3 is a diagram schematically showing a state in which the droplet 20 is wet and spread when the droplet 20 is placed on the substrate surface 10S (a) and pressed by a mold from above the paper surface. For easy understanding, it is shown as a schematic diagram when a mold having a smooth surface is pressed. FIG. 3B is a schematic view showing a state in which the droplet 20 is crushed by pressure contact and spreading wet, and the surfactant is unevenly distributed in the hatched portion and the surface of the mold not shown in the drawing. . When the press contact is continued, an uneven distribution pattern of the fluorine-containing surfactant 22 is formed according to the arrangement of the droplets 20 as shown in FIG. In FIG. 3 (c), the surfactant 22 is actually present on the surface of the portion labeled 21, but the illustration is omitted for easy understanding. In addition, when a material having high compatibility with the surfactant is applied as a mold release agent to the surface of the mold to be in pressure contact, the surfactant 22 is placed at the top of the approximate center of the droplet 20 that first contacts the mold surface. May be ubiquitous. Therefore, the resist layer 20m is cured by being irradiated with the light L1 in a state where the uneven distribution pattern shown in FIG. Become.

  Conventionally, since this unevenly distributed surfactant does not have polymerizability, what exists on the contact surface with the mold 30 deteriorates the pattern surface of the mold 30 due to adhesion and accumulation of the surfactant on the mold 30, Moreover, since the surfactant unevenly distributed in the hatched portion in FIG. 3C cannot be cured, it causes a pattern defect (inkjet arrangement pattern defect).

  The resist composition used in the present invention contains a polymerizable fluorine-containing compound (fluorine-containing polymerizable compound) as a surfactant. The fluorine-containing compound generally has a property of being unevenly distributed in the interface layer in the resin layer, and the higher the fluorine substitution rate in the compound, the greater the uneven distribution, and even in the imprint method to which the present invention is applied, the post-curing Since it is mainly unevenly distributed at the interface between the resist layer and the mold, deterioration of the pattern surface of the mold is a problem of mass productivity.

  The purpose of including the fluorine-containing compound in the resist composition is that the fluorine-containing compound is unevenly distributed in the interface layer between the mold and the resist, and the fluorine-containing compound has low adhesion to the mold. In addition to the purpose of improving mold releasability in the peeling process by showing lubricity, film forming ability by methods such as ink jet and printing methods can be improved by controlling surface energy when forming a resist on a substrate. It also has the purpose of stabilizing.

  In the present invention, a fluorine-containing polymerizable compound is used as the fluorine-containing compound that is unevenly distributed in the mold-side interface layer of the resist layer. In the present invention, the polymerizable group of the fluorine-containing polymerizable compound is a functional group having polymerization reactivity with the main component monomer of the resist composition, preferably a (meth) acryl group. By containing a polymerizable group in the fluorine-containing compound, the fluorine-containing compound adheres to the mold after imprinting and suppresses deterioration of the mold quality due to the accumulation, and also improves the good releasability and film formation stability. I found that I can maintain it.

  That is, by using the fluorine-containing polymerizable compound as a surfactant in the resist composition 20, the hatched portion of the surfactant in FIG. Since it is hardened as a part of a pattern having good etching resistance, the possibility of pattern defects due to uneven distribution of the surfactant 22 becomes extremely low. In addition, since the surfactant 22 present on the contact surface with the mold 30 is also polymerized and cured, it is possible to suppress deterioration in pattern quality due to adhesion of the mold 30 to the pattern surface. In addition, by selecting a surfactant that is efficient in terms of surface activity such as surface unevenness and surface stabilization performance due to uneven distribution and releasability, the amount used can be greatly reduced, and the interface on a two-dimensional plane can be reduced. Corresponding to the distribution of the amount of the activator, the influence of the quality deterioration of the post-etching shape can be made a level that cannot be substantially discriminated.

  The present inventor has designed a material having resist characteristics with good releasability and etching resistance for the polymerizable compound 21 and the fluorine-containing polymerizable surfactant 22 which are the main components of the resist composition 20.

  Below, the resist composition 20 is demonstrated in detail. The resist composition 20 is a curable composition for imprints containing at least a polymerizable surfactant (fluorine-containing polymerizable surfactant 22) containing at least one fluorine, a polymerizable compound 21, and a photopolymerization initiator I. It is a thing.

  The resist composition 20 aims at the expression of crosslinkability by having a polyfunctional polymerizable group as a function, increases the carbon density, increases the total amount of binding energy, or contains O in the resin after curing. , S, N, and the like may contain a monomer component having one or more functional groups having a polymerizable functional group for the purpose of improving the etching resistance by suppressing the content of a portion having a high electronegativity, etc. In addition, a coupling agent with the substrate, a volatile solvent, an antioxidant and the like may be included.

  As the coupling agent with the substrate, the same material as the adhesion treatment agent for the substrate described above can be used. As content, it should just be contained to the extent arrange | positioned in the interface of a board | substrate and a resist layer, it should just be 10 mass% or less, 5 mass% or less is more preferable, 2 mass% or less is still more preferable, Most preferably, it is 0.5 mass% or less.

  The viscosity of the resist composition 20 is such that the solid content (components excluding the volatile solvent component) in the resist composition into the pattern formed on the mold 30 and the wettability of the mold in the mold are considered. Is preferably 1000 mPa · s or less, more preferably 100 mPa · s or less, and even more preferably 20 mPa · s or less. However, when inkjet is used, it is preferable that the temperature is within a temperature range of 15 mPa · s or less if the temperature can be controlled at the time of ejection with a head or a head, and the surface tension of the resist composition is 20 to 35 (mN). / M) is preferable from the viewpoint of securing the ejection stability in the inkjet.

(Polymerizable compound)
In the item of “Background Art”, it was described that the fluorine content in the polymerizable compound which is the main component of the resist 20 is preferably low in terms of etching resistance. Therefore, in the present invention, the polymerizable compound 21 which is the main component of the resist 20 has a fluorine content in the compound represented by the above formula (C1) of 5% or less, or a fluoroalkyl group or fluoroalkyl. The polymerizable compound does not substantially contain an ether group.

  Although it does not restrict | limit especially as the polymeric compound 21, It is preferable that it is a thing with favorable quality, such as the precision of the pattern after hardening, and etching tolerance. The present inventors preferably include, as such a polymerizable compound 21, a polyfunctional monomer that is crosslinked by polymerization to become a polymer having a three-dimensional structure, and the polyfunctional monomer includes at least one 2 It has been found that it is preferable to have a valent or trivalent aromatic group.

  In the case of a resist having a three-dimensional structure after curing (polymerization), the shape maintenance property after curing is good, and the stress applied to the resist is concentrated on a specific area of the resist structure due to the adhesive force between the mold and the resist when the mold is peeled off. In addition, the plastic deformation of the pattern is suppressed.

  However, when the ratio of the polyfunctional monomer that becomes a polymer having a three-dimensional structure after polymerization and the density of the site that forms three-dimensional crosslinks after polymerization increase, the Young's modulus after curing increases and the deformability decreases, Moreover, since the brittleness of the film is deteriorated, there is a concern that the film may be easily broken at the time of mold peeling. In particular, in an aspect in which the pattern size is 30 nm width or less and the pattern aspect ratio is 2 or more, and the remaining film thickness is 10 nm or less, when the formation in a wide area such as a hard disk pattern or a semiconductor pattern is attempted, pattern peeling or It is thought that the probability that moge will occur increases.

  Therefore, the polyfunctional monomer is preferably contained in the polymerizable compound 21 in an amount of 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more. Most preferably, it is 40 mass% or more.

In addition, the crosslinking density represented by the following formula (C2) is preferably 0.01 piece / nm ² or more and 10 pieces / nm ² or less, and preferably 0.1 piece / nm ² or more and 6 pieces / nm ² or less. It was more preferable that it was most preferably 0.5 / nm ² or more and 5.0 / nm ² or less. The crosslinking density of the composition is a value obtained by calculating the crosslinking density of each molecule and further obtaining from the weight average, or measuring the density after curing of the composition, and calculating the weight average of each value for Mw and (Nf-1). And the equation (C2).
Formula (C2)

(Da: crosslinking density of one molecule, Dc: density after curing, Nf: number of acrylate functional groups contained in one monomer molecule, Na: Avogadro constant, Mw: molecular weight)

  The polymerizable functional group of the polymerizable compound 21 is not particularly limited, but a methacrylate group and an acrylate group are preferable and an acrylate group is more preferable because of good reactivity and stability.

  The dry etching resistance can be evaluated by the Onishi parameter and the ring parameter of the resist composition. The smaller the Onishi parameter and the larger the ring parameter, the better the dry etching resistance. In the present invention, the resist composition 20 has an Onishi parameter of 4.0 or less, preferably 3.5 or less, more preferably 3.0 or less, and a ring parameter of 0.1 or more, preferably 0. .2 or more, more preferably 0.3 or more is suitable.

The above parameters are the material parameter values calculated using the calculation formulas described below based on the structural formulas for the constituent materials other than the volatile solvent components constituting the resist composition 20, and the entire composition based on the composition weight ratio. Calculated as the value averaged by. Therefore, it is preferable to select the polymerizable compound 21 which is the main component of the resist composition 20 in consideration of the other components in the resist composition 20 and the above parameters.
Onishi parameter = (total number of atoms in compound) / (number of carbon atoms in compound) − (number of oxygen atoms in compound)
Ring parameter = (mass of carbon forming the ring structure) / (total mass of compound)

  Examples of the polymerizable compound 21 include the following polymerizable monomers and oligomers obtained by polymerizing several units of such polymerizable monomers. From the viewpoint of pattern formability and etching resistance, it is preferable to contain at least one of a polymerizable monomer (Ax) and compounds described in JP-A-2009-218550 [0032] to [0053].

-Polymerizable monomer (Ax)-
The polymerizable monomer (Ax) is represented by the following general formula (I).

[In the formula, Ar represents a divalent or trivalent aromatic group which may have a substituent, X represents a single bond or an organic linking group, and R ¹ has a hydrogen atom or a substituent. Represents an optionally substituted alkyl group, and n represents 2 or 3. ]

  In general formula (I), Ar represents a divalent aromatic group (ie, an arylene group) when n = 2, and represents a trivalent aromatic group when n = 3. Examples of the arylene group include hydrocarbon-based arylene groups such as a phenylene group and a naphthylene group; heteroarylene groups in which indole, carbazole and the like are linked groups, preferably a hydrocarbon-based arylene group, and more preferably a viscosity, From the viewpoint of etching resistance, it is a phenylene group. The arylene group may have a substituent, and preferred examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, a cyano group, an alkoxycarbonyl group, an amide group, and a sulfonamide group.

  Examples of the organic linking group for X include an alkylene group, an arylene group, and an aralkylene group, which may contain a hetero atom in the chain. Among these, an alkylene group and an oxyalkylene group are preferable, and an alkylene group is more preferable. X is particularly preferably a single bond or an alkylene group.

R ¹ is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom. When R ¹ has a substituent, preferred substituents are not particularly limited, and examples thereof include a hydroxyl group, a halogen atom (excluding fluorine), an alkoxy group, and an acyloxy group. n is 2 or 3, preferably 2.

The polymerizable monomer (Ax) is preferably a polymerizable monomer represented by the following general formula (Ia) or (Ib) from the viewpoint of reducing the composition viscosity.

[Wherein, X ¹ and X ² each independently represents a single bond or an alkylene group which may have a substituent of 1 to 3 carbon atoms, and R ¹ has a hydrogen atom or a substituent. Represents a good alkyl group. ]
In general formula (Ia), X ¹ is preferably a single bond or a methylene group, and more preferably a methylene group from the viewpoint of viscosity reduction. The preferable range of X ^{2 is the same as} the preferable range of X ¹ .

R ¹ has the same meaning as R ¹ in formula (I), and the preferred range is also the same.

  When the polymerizable monomer (Ax) is liquid at 25 ° C., it is preferable that generation of foreign matters can be suppressed even when the addition amount is increased.

  The polymerizable monomer (Ax) preferably has a viscosity at 25 ° C. of less than 70 mPa · s from the viewpoint of pattern formation, more preferably 50 mPa · s or less, and particularly preferably 30 mPa · s or less. preferable.

Specific examples of preferred polymerizable monomers (Ax) are shown. R ¹ has the same meaning as R ¹ in the general formula (I). R ¹ is preferably a hydrogen atom from the viewpoint of curability. The present invention is not limited to these specific examples.

Among these, the compounds shown below are particularly preferable because they are liquid at 25 ° C., have low viscosity, and exhibit better curability.

  In the resist composition 20, from the viewpoint of improving the composition viscosity, dry etching resistance, imprint suitability, curability, and the like, a polymerizable monomer (Ax) and a polymerizable monomer described below as necessary. It is preferable to use in combination with another polymerizable monomer different from the body (Ax).

-Other polymerizable monomers-
Examples of other polymerizable monomers include polymerizable unsaturated monomers having 1 to 6 ethylenically unsaturated bond-containing groups; compounds having an oxirane ring (epoxy compounds); vinyl ether compounds; styrene derivatives; A compound having an atom; propenyl ether or butenyl ether can be exemplified, and a polymerizable unsaturated monomer having 1 to 6 ethylenically unsaturated bond-containing groups is preferable from the viewpoint of curability.

    Among these other polymerizable monomers, from the viewpoints of imprint suitability, dry etching resistance, curability, viscosity, and the like, the compounds described in JP-A-2009-218550 [0032] to [0053] are more preferably included. I can do it.

  Furthermore, the polymerizable unsaturated monomer (1-6 functional polymerizable unsaturated monomer) which has 1-6 the said ethylenically unsaturated bond containing group which can be contained is demonstrated.

  First, specific examples of the polymerizable unsaturated monomer having one ethylenically unsaturated bond-containing group (monofunctional polymerizable unsaturated monomer) include 2-acryloyloxyethyl phthalate, 2-acryloyloxy 2 -Hydroxyethyl phthalate, 2-acryloyloxyethyl hexahydrophthalate, 2-acryloyloxypropyl phthalate, 2-ethyl-2-butylpropanediol acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl carbitol (meth) Acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 4-hydroxy Butyl (medium ) Acrylate, acrylic acid dimer, benzyl (meth) acrylate, 1- or 2-naphthyl (meth) acrylate, butanediol mono (meth) acrylate, butoxyethyl (meth) acrylate, butyl (meth) acrylate, cetyl (meth) acrylate , Ethylene oxide modified (hereinafter referred to as “EO”) cresol (meth) acrylate, dipropylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate, ethyl (meth) acrylate, isoamyl (meth) acrylate, isobutyl (meth) acrylate , Isooctyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclohentanyl (meth) acrylate, dicyclopentanyloxye (Meth) acrylate, isomyristyl (meth) acrylate, lauryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxytriethylene glycol ( (Meth) acrylate, methyl (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolypropylene glycol (meth) acrylate, octyl (meth) acrylate, paracumylphenoxyethylene glycol (meth) ) Acrylate, epichlorohydrin (hereinafter referred to as “ECH”) modified phenoxy acrylate, phenoxyethyl (meth) ) Acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyhexaethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polypropylene glycol (meth) Acrylate, stearyl (meth) acrylate, EO modified succinic acid (meth) acrylate, tert-butyl (meth) acrylate, tribromophenyl (meth) acrylate, EO modified tribromophenyl (meth) acrylate, tridodecyl (meth) acrylate, p -Isopropenylphenol, styrene, α-methylstyrene, acrylonitrile are exemplified.

    Among these, a monofunctional (meth) acrylate having an aromatic structure and / or an alicyclic hydrocarbon structure is particularly preferable from the viewpoint of improving dry etching resistance. Specific examples benzyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate and adamantyl (meth) acrylate are preferred, and benzyl (meth) acrylate is particularly preferred preferable.

    It is also preferable to use a polyfunctional polymerizable unsaturated monomer having two ethylenically unsaturated bond-containing groups as the other polymerizable monomer. Examples of the bifunctional polymerizable unsaturated monomer having two ethylenically unsaturated bond-containing groups that can be preferably used include diethylene glycol monoethyl ether (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, Di (meth) acrylated isocyanurate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, EO modified 1,6-hexanediol di (meth) acrylate, ECH modified 1 , 6-hexanediol di (meth) acrylate, allyloxy polyethylene glycol acrylate, 1,9-nonanediol di (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di (meth) acrylate, modified Bisfeneau A di (meth) acrylate, EO-modified bisphenol F di (meth) acrylate, ECH-modified hexahydrophthalic acid diacrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, EO-modified neo Pentyl glycol diacrylate, propylene oxide (hereinafter referred to as “PO”) modified neopentyl glycol diacrylate, caprolactone modified hydroxypivalate ester neopentyl glycol, stearic acid modified pentaerythritol di (meth) acrylate, ECH modified phthalic acid di (meta) ) Acrylate, poly (ethylene glycol-tetramethylene glycol) di (meth) acrylate, poly (propylene glycol-tetramethylene glycol) (Meth) acrylate, polyester (di) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ECH-modified propylene glycol di (meth) acrylate, silicone di (meth) acrylate, triethylene glycol di (meth) ) Acrylate, tetraethylene glycol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, neopentyl glycol modified trimethylol propane di (meth) acrylate, tripropylene glycol di (meth) acrylate, EO modified tripropylene glycol Di (meth) acrylate, triglycerol di (meth) acrylate, dipropylene glycol di (meth) acrylate, divinylethylene urea, Divinyl propylene urea is exemplified.

    Among these, neopentyl glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, neopentyl hydroxypivalate Glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and the like are preferably used in the present invention.

    Examples of the polyfunctional polymerizable unsaturated monomer having 3 or more ethylenically unsaturated bond-containing groups include ECH-modified glycerol tri (meth) acrylate, EO-modified glycerol tri (meth) acrylate, PO-modified glycerol tri (meta) ) Acrylate, pentaerythritol triacrylate, EO modified phosphoric acid triacrylate, trimethylolpropane tri (meth) acrylate, caprolactone modified trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylol Propane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) Chlorate, dipentaerythritol hydroxypenta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol poly (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) Examples include acrylate, pentaerythritol ethoxytetra (meth) acrylate, and pentaerythritol tetra (meth) acrylate.

    Among these, EO-modified glycerol tri (meth) acrylate, PO-modified glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate and the like are preferably used in the present invention.

    Examples of the compound having an oxirane ring (epoxy compound) include polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycol, and polyglycidyl ethers of aromatic polyols. And hydrogenated compounds of polyglycidyl ethers of aromatic polyols, urethane polyepoxy compounds and epoxidized polybutadienes. These compounds can be used alone or in combination of two or more thereof.

    Examples of the compound having an oxirane ring (epoxy compound) that can be preferably used in the present invention include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, bromine Bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 1,4-butanediol diglycidyl ether, 1 , 6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol jig Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin; Diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; monoglycidyl ethers of polyether alcohols obtained by adding phenol, cresol, butylphenol or alkylene oxide to these; higher fatty acid Examples thereof include glycidyl esters.

    Among these, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol Diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether are preferred.

  Commercially available products that can be suitably used as the glycidyl group-containing compound include UVR-6216 (manufactured by Union Carbide), glycidol, AOEX24, cyclomer A200, (manufactured by Daicel Chemical Industries, Ltd.), Epicoat 828, Epicoat 812, Epicoat 1031, Epicoat 872, Epicoat CT508 (above, manufactured by Yuka Shell Co., Ltd.), KRM-2400, KRM-2410, KRM-2408, KRM-2490, KRM-2720, KRM-2750 (above, Asahi Denka Kogyo ( Product)). These can be used alone or in combination of two or more.

    The production method of these compounds having an oxirane ring is not limited. For example, Maruzen KK Publishing, 4th edition Experimental Chemistry Course 20 Organic Synthesis II, 213, 1992, Ed. By Alfred Hasfner, The chemistry of cyclic compounds-Small Ring Heterocycles part 3 Oxiranes, John & Wiley and Sons, An Interscience Publication, New York, 1985, Yoshimura, Adhesion, Vol. 29, No. 12, 32, 1985, Yoshimura, Adhesion, Vol. 30, No. 5, 42, 1986, Yoshimura, Adhesion, Vol. 30, No. 7, 42, 1986, Japanese Patent Application Laid-Open No. 11-1000037, Japanese Patent No. 2906245, Japanese Patent No. 2926262 and the like can be synthesized.

  As other polymerizable monomer used in the present invention, a vinyl ether compound may be used in combination. As the vinyl ether compound, known compounds can be appropriately selected. For example, 2-ethylhexyl vinyl ether, butanediol-1,4-divinyl ether, diethylene glycol monovinyl ether, diethylene glycol monovinyl ether, ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,3-propanediol divinyl ether, 1,3-butanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylol Propane trivinyl ether, trimethylol ethane trivinyl ether, hexanediol divinyl ether, tetra Tylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, ethylene glycol diethylene vinyl ether, triethylene glycol diethylene vinyl ether, ethylene glycol dipropylene vinyl ether, triethylene glycol diethylene vinyl ether , Trimethylolpropane triethylene vinyl ether, trimethylolpropane diethylene vinyl ether, pentaerythritol diethylene vinyl ether, pentaerythritol triethylene vinyl ether, pentaerythritol tetraethylene vinyl ether, 1,1,1-to Scan [4- (2-vinyloxy ethoxy) phenyl] ethane, bisphenol A divinyloxyethyl carboxyethyl ether.

    These vinyl ether compounds can be obtained, for example, by the method described in Stephen C. Lapin, Polymers Paint Color Journal. They can be synthesized by the reaction of a polyhydric alcohol or polyhydric phenol and a halogenated alkyl vinyl ether, and these can be used singly or in combination of two or more.

  Further, as other polymerizable monomer, a styrene derivative can also be employed. Examples of styrene derivatives include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methylstyrene, p-hydroxy. Examples include styrene.

    In addition, trifluoroethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, (perfluorobutyl) ethyl (meth) acrylate, perfluorobutyl-hydroxypropyl ( Use compounds containing fluorine atoms such as (meth) acrylate, (perfluorohexyl) ethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, etc. Can do.

    As other polymerizable monomer, propenyl ether and butenyl ether can also be used. Examples of the propenyl ether or butenyl ether include 1-dodecyl-1-propenyl ether, 1-dodecyl-1-butenyl ether, 1-butenoxymethyl-2-norbornene, 1-4-di (1-butenoxy) butane, 1,10-di (1-butenoxy) decane, 1,4-di (1-butenoxymethyl) cyclohexane, diethylene glycol di (1-butenyl) ether, 1,2,3-tri (1-butenoxy) propane, propenyl ether propylene Carbonate or the like can be suitably applied.

(Fluorine-containing polymerizable surfactant)
The fluorine-containing polymerizable surfactant 22 is not particularly limited as long as it is a polymerizable compound such as a monomer or oligomer having at least one functional group having a fluorine atom and at least one polymerizable functional group. In order to enable easy pattern formation, it is preferable to have a steric configuration that allows easy polymerization with the polymerizable compound 21.

  In the present embodiment, the fluorine-containing polymerizable surfactant 22 is a part of the resist pattern, and thus has good pattern formability, mold releasability after curing, and resist characteristics with good etching resistance. It is preferable.

  The content of the fluorine-containing polymerizable surfactant 22 in the resist composition 20 is, for example, 0.001 to 5% by mass, preferably 0.002 to 4% by mass, and more preferably 0.005. ˜3 mass%. When using 2 or more types of surfactant, the total amount becomes the said range. When the surfactant is in the range of 0.001 to 5% by mass in the composition, the effect of coating uniformity is good, the deterioration of mold transfer characteristics due to excessive surfactant, and the etching process after imprinting It is difficult to cause deterioration of etching suitability.

  The fluorine-containing polymerizable surfactant 22 preferably has a polymerizable group at its side chain, particularly at the terminal. Examples of the polymerizable functional group include radical polymerizable functional groups such as (meth) acrylate group, (meth) acrylamide group, vinyl group and allyl group, and cationic polymerizable functional groups such as epoxy group, oxetanyl group and vinyl ether group. A radical polymerizable functional group, more preferably an ethylenically unsaturated bond group such as a (meth) acrylate group.

  The group having a fluorine atom of the fluorine-containing polymerizable surfactant 22 is preferably a fluorine-containing group selected from a fluoroalkyl group and a fluoroalkyl ether group.

  The fluoroalkyl group is preferably a fluoroalkyl group having 2 or more carbon atoms, more preferably a fluoroalkyl group having 4 or more carbon atoms, and the upper limit is not particularly defined, but 20 or less is preferable. 8 or less is more preferable, and 6 or less is more preferable. Most preferably, it is a C4-C6 fluoroalkyl group. Examples of the preferred fluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a hexafluoroisopropyl group, a nonafluorobutyl group, a tridecafluorohexyl group, and a heptadecafluorooctyl group.

In the pattern forming method of the present invention, the fluorine-containing polymerizable surfactant 22 is preferably a polymerizable compound having a fluorine atom having a trifluoromethyl group structure. That is, at least one of the fluoroalkyl groups preferably contains a trifluoromethyl group structure. By having a trifluoromethyl group structure, the effect of the present invention is exhibited even with a small addition amount (for example, 10% by mass or less), and the surface energy is reduced and the releasability is improved. As in the case of the alkyl group, those having a trifluoromethyl group are preferred, and those containing a perfluoroethyleneoxy group and a perfluoropropyleneoxy group are preferred. A fluoroalkyl ether unit having a trifluoromethyl group such as — (CF (CF ₃ ) CF ₂ O) — and / or a trifluoromethyl ether group having a trifluoromethyl group at the terminal thereof are preferred.

  In the pattern forming method of the present invention, a particularly preferred embodiment of the fluorine-containing polymerizable surfactant 22 contains at least two fluorine-containing groups selected from a fluoroalkyl group and a fluoroalkyl ether group, and At least two are polymerizable monomers separated by a linking group having 2 or more carbon atoms. That is, when the polymerizable monomer has two fluorine-containing groups, the two fluorine-containing groups are separated by a linking group having 2 or more carbon atoms, and the polymerizable monomer has 3 fluorine-containing groups. When two or more are present, at least two of them are separated by a linking group having 2 or more carbon atoms, and the remaining fluorine-containing groups may have any bonding form. The linking group having 2 or more carbon atoms is a linking group having at least two carbon atoms that are not substituted with fluorine atoms.

From the same viewpoint, a polymerizable monomer containing three or more trifluoromethyl group structures is also preferred, and a polymerizable monomer containing 3 to 9, more preferably 4 to 6 trifluoromethyl group structures is preferred. preferable. Examples of the compound containing three or more trifluoromethyl group structures include a branched fluoroalkyl group having two or more trifluoromethyl groups in one fluorine-containing group, such as —CH (CF ₃ ) ₂ group, —C (CF ₃ ) ₃ , a compound having a fluoroalkyl group such as a —CCH ₃ (CF ₃ ) ₂ CH ₃ group is preferred.

As the fluoroalkyl ether group, those having a trifluoromethyl group are preferred, and those containing a perfluoroethyleneoxy group or a perfluoropropyleneoxy group are preferred. A fluoroalkyl ether unit having a trifluoromethyl group such as — (CF (CF ₃ ) CF ₂ O) — and / or a trifluoromethyl ether group having a trifluoromethyl group at the terminal thereof are preferred.

  Examples of the functional group contained in the linking group having 2 or more carbon atoms include an alkylene group, an ester group, a sulfide group, and an arylene group, and it is more preferable to have at least an ester group and / or a sulfide group.

  The linking group having 2 or more carbon atoms is preferably an alkylene group, an ester group, a sulfide group, an arylene group, or a combination thereof.

  These groups may have a substituent without departing from the gist of the present invention.

  The number of total fluorine atoms contained in the fluorine-containing polymerizable surfactant 22 is preferably 6 to 60, more preferably 9 to 40, and further preferably 12 to 40 per molecule.

  The fluorine-containing polymerizable surfactant 22 is preferably a polymerizable compound having a fluorine atom having a fluorine content of 20 to 60% as defined below, and the fluorine-containing polymerizable surfactant 22 is a polymerizable monomer. In this case, it is more preferably 30 to 60%, and further preferably 35 to 60%. When the fluorine-containing polymerizable surfactant 22 is an oligomer having a polymerizable group, the fluorine content is more preferably 20 to 50%, and further preferably 20 to 40%. By making the fluorine content within an appropriate range, compatibility with other components is excellent, mold stains can be reduced, and compatibility with mold release properties can be achieved, thereby improving the repeat pattern forming property, which is an effect of the present invention. Similar to the polymerizable compound, the fluorine content is represented by the following formula (C1).

Formula (C1)

As one preferred form of the fluorine-containing polymerizable surfactant 22, a compound (monomer) having a partial structure represented by the following general formula (II-a) is given as a preferred example of a group having a fluorine atom. Can be mentioned. By adopting a compound having such a partial structure, the pattern forming property is excellent even when repeated pattern transfer is performed, and the temporal stability of the composition is improved.

  [In Formula (II-a), n represents an integer of 1 to 8, preferably an integer of 4 to 6. ]

Another preferred example of the fluorine-containing polymerizable surfactant 22 is a compound having a partial structure represented by the following general formula (IV). Of course, you may have both the partial structure represented by general formula (II), and the partial structure represented by general formula (II-b).

[In General Formula (II-b), L ¹ represents a single bond or an alkylene group having 1 to 8 carbon atoms, L ² represents an alkylene group having 1 to 8 carbon atoms, and m1 and m2 are each 0 or 1 And at least one of m1 and m2 is 1. m3 represents an integer of 1 to 3, p represents an integer of 1 to 8, and when m3 is 2 or more, -C _p F _{2p + 1} may be the same or different. ]
L ¹ and L ² are each preferably an alkylene group having 1 to 4 carbon atoms. Moreover, the alkylene group may have a substituent within the range which does not deviate from the meaning of this invention. m3 is preferably 1 or 2. p is preferably an integer of 4 to 6.

A polymerizable monomer represented by the following general formula (II-c) is preferable.

[In General Formula (II-c), R ¹ represents a hydrogen atom, an alkyl group, a halogen atom or a cyano group, A represents an (a1 + a2) -valent linking group, and a1 represents an integer of 1 to 6. a2 represents an integer of 2 to 6, and R ² and R ³ each represent an alkylene group having 1 to 8 carbon atoms. m1 and m2 each represents 0 or 1, and at least one of m1 and m2 is 1. m3 represents an integer of 1 to 3. m4 and m5 each represents 0 or 1, at least one of m4 and m5 is 1, and when both m1 and m2 are 1, m4 is 1. n represents an integer of 1 to 8. ]
R ¹ is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

  A is preferably a linking group having an alkylene group and / or an arylene group, and may further contain a linking group containing a hetero atom. Examples of the linking group having a hetero atom include —O—, —C (═O) O—, —S—, and —C (═O) —. These groups may have a substituent within a range not departing from the gist of the present invention, but preferably do not have a substituent. A preferably has 2 to 50 carbon atoms, and more preferably 4 to 15 carbon atoms.

  a1 is preferably 1 to 3, more preferably 1 or 2. a2 is preferably 2 or 3, more preferably 2.

  When a1 is 2 or more, each A may be the same or different.

When a2 is 2 or more, R ² , R ³ , m1, m2, m3, m4, m5 and n may be the same or different.

  The molecular weight of the polymerizable monomer used as the fluorine-containing polymerizable surfactant 22 used in the pattern forming method of the present invention is preferably 500 to 2,000. Moreover, the viscosity of this polymerizable monomer becomes like this. Preferably it is 600-1500, More preferably, it is 600-1200.

Specific examples of the polymerizable monomer used as the fluorine-containing polymerizable surfactant 22 are given below, but the present invention is not limited thereto. R ¹ in the following formula is any one of a hydrogen atom, an alkyl group, a halogen atom and a cyano group.

  Other polymerizable monomers used as the fluorine-containing polymerizable surfactant 22 include trifluoroethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, (perfluorobutyl) ethyl (meth) acrylate, Fluorobutyl-hydroxypropyl (meth) acrylate, (perfluorohexyl) ethyl (meth) acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl ( A monofunctional polymerizable compound having a fluorine atom such as (meth) acrylate may be mentioned. Examples of the polymerizable compound having a fluorine atom include 2,2,3,3,4,4-hexafluoropentane di (meth) acrylate, 2,2,3,3,4,4,5,5- A polyfunctional polymerizable compound having two or more polymerizable functional groups having a di (meth) acrylate having a fluoroalkylene group such as octafluorohexane di (meth) acrylate is also preferred.

  A compound having two or more fluorine-containing groups such as a fluoroalkyl group or a fluoroalkyl ether group in one molecule can also be preferably used.

  When the polymerizable compound having a fluorine atom is an oligomer or the like, those containing the polymerizable monomer as a repeating unit are preferred.

  In addition, compounds described in JP-A-2006-114882 [0018] to [0048], fluorine-containing polymerizable compounds described in JP-A-2008-95037 [0027] to [0035], and the like can be used as the surfactant. .

  A synthesis example of the fluorine-containing polymerizable compound 22 used in the present invention is shown as one specific example.

[Synthesis Example 1]
(Synthesis of fluorinated polymerizable monomer Ax-1)
To 2 g of thioerythritol, 45 ml of ethanol and 5 ml of water were added and dissolved, and 1.1 g of sodium hydroxide was added thereto and stirred at room temperature for 30 minutes. 0.2g and 15.4g of perfluorohexyl ethyl iodide were added to this, and it was made to react at 90 degreeC for 7 hours. Ethyl acetate was added to the reaction solution, and the organic phase was washed successively with water and saturated brine, dried and concentrated to give (Ax-1a).

  6.7 g of (Ax-1a) was dissolved in 80 ml of acetone, and 3.2 g of triethylamine was added thereto. Further, 2.5 g of acrylic acid chloride was added dropwise under ice cooling. After the dropwise addition, the mixture was reacted at room temperature for 20 hours, 50 ml of water was added to the reaction solution, and this was extracted with ethyl acetate. The organic phase was washed with 1N hydrochloric acid aqueous solution, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried and concentrated to obtain a crude product. When this was purified by column chromatography, 2.8 g of a polymerizable monomer Ax-1 was obtained.

¹ H-NMR (CDCl ₃ ): δ 2.2-2.5 (m, 4H), δ 2.7-3.0 (m, 8H), δ 5.4 (m, 2H), δ 5.95 (d, 2H), δ6.1 (dd, 2H), δ6.45 (d, 2H)

[Synthesis Example 2]
(Synthesis of polymerizable monomer Ax-2)
2 g of dithioerythritol was dissolved in 20 ml of ethyl acetate, 0.2 g of triethylamine and 11.4 g of perfluorohexylethyl acrylate were added thereto, and the mixture was reacted at room temperature for 4 hours. To the reaction solution, 4.0 g of triethylamine and 20 ml of ethyl acetate were added, and 2.9 g of acrylic acid chloride was added dropwise thereto under ice cooling. After the dropwise addition, the mixture was reacted at room temperature for 20 hours, and then 50 ml of water was added to the reaction solution and stirred. The organic phase was washed with 1N hydrochloric acid aqueous solution, saturated aqueous sodium hydrogen carbonate solution and saturated brine, dried and concentrated to obtain a crude product. When this was purified by column chromatography, 3 g of a polymerizable monomer Ax-2 was obtained.

¹ H-NMR (CDCl ₃ ): δ 2.4-3.0 (m, 16H), δ 4.4 (t, 4H), δ 5.4 (m, 2H), δ 5.9 (d, 2H), δ 6 .1 (dd, 2H), δ 6.45 (d, 2H)

[Synthesis Example 3]
Polymerizable monomers (Ax-3) to (Ax-7) were synthesized using the same method as in Synthesis Examples 1 and 2.

¹ H-NMR (CDCl ₃ )
(Ax-3)
δ2.3-2.6 (m, 4H), δ2.8-3.0 (m, 6H), δ3.1 (m, 1H), δ4.4 (m, 2H), δ5.9 (d, 2H), δ6.1 (dd, 2H), δ6.45 (d, 2H)
(Ax-4)
δ 2.2-2.6 (m, 4H), δ 2.7-3.0 (m, 8H), δ 5.4 (m, 2H), δ 5.95 (d, 2H), δ 6.1 (dd, 2H), δ 6.45 (d, 2H)
(Ax-5)
δ2.8-3.0 (m, 12H), δ5.4 (m, 2H), δ5.8 (m, 2H), δ5.9 (d, 2H), δ6.1 (dd, 2H), δ6 .45 (d, 2H)
(Ax-6)
δ2.8-3.0 (m, 12H), δ3.1 (m, 1H), δ4.4 (m, 2H), δ5.8 (m, 2H), δ5.9 (d, 1H), δ6 .1 (dd, 1H), δ 6.45 (d, 1H)
(Ax-7)
δ2.3-2.6 (m, 4H), δ2.8-3.0 (m, 6H), δ3.1 (m, 1H), δ4.4 (m, 2H), δ5.9 (d, 2H), δ6.1 (dd, 2H), δ6.45 (d, 2H)

(Polymerization initiator I)
The polymerization initiator I is not particularly limited as long as it generates an active species that is activated by the light L1 used when the resist composition 20 is cured to start polymerization of the polymerizable compound contained in the resist composition 20. . As the polymerization initiator I, a radical polymerization initiator is preferable. Moreover, in this invention, the polymerization initiator I may use multiple types together.

  As the polymerization initiator I, acylphosphine oxide compounds and oxime ester compounds are preferable from the viewpoints of curing sensitivity and absorption characteristics. For example, those described in paragraph No. 0091 of JP-A No. 2008-105414 are preferably employed. Can do.

  The content of the polymerization initiator I is, for example, 0.01 to 15% by mass, preferably 0.1 to 12% by mass, and more preferably 0.2 to 7% by mass in the entire composition excluding the solvent. %. When using 2 or more types of photoinitiators, the total amount becomes the said range.

  When the content of the photopolymerization initiator is 0.01% by mass or more, the sensitivity (fast curability), resolution, line edge roughness, and coating strength tend to be improved, which is preferable. On the other hand, when the content of the photopolymerization initiator is 15% by mass or less, light transmittance, colorability, handleability and the like tend to be improved, which is preferable.

  So far, various addition amounts of preferred photopolymerization initiators have been studied for ink-jet compositions and dye- and / or pigment-containing compositions for liquid crystal display color filters, but for photo-imprints such as imprints. There is no report about the preferable addition amount of the photopolymerization initiator for the curable composition. That is, in a system containing a dye and / or pigment, the initiator may act as a radical trapping agent, which affects the photopolymerization and sensitivity. In consideration of this point, the amount of the photopolymerization initiator added is optimized in these applications. On the other hand, in the resist composition 20, dyes and / or pigments are not essential components, and the optimal range of the photopolymerization initiator may be different from those in the fields of ink jet compositions and liquid crystal display color filter compositions. is there.

    As the radical photopolymerization initiator used in the present invention, acylphosphine compounds and oxime ester compounds are preferable from the viewpoints of curing sensitivity and absorption characteristics. As the radical photopolymerization initiator used in the present invention, for example, a commercially available initiator can be used. As these examples, for example, those described in paragraph No. 0091 of JP-A No. 2008-105414 can be preferably used.

    Note that the light L1 includes not only light having a wavelength in the ultraviolet, near-ultraviolet, far-ultraviolet, visible, and infrared regions, and electromagnetic waves, but also radiation. Examples of the radiation include microwaves, electron beams, EUV, and X-rays. Laser light such as a 248 nm excimer laser, a 193 nm excimer laser, and a 172 nm excimer laser can also be used. The light may be monochromatic light (single wavelength light) that has passed through an optical filter, or may be light with a plurality of different wavelengths (composite light). The exposure can be multiple exposure, and the entire surface can be exposed after forming a pattern for the purpose of increasing the film strength and etching resistance.

  The photopolymerization initiator I needs to be selected in a timely manner with respect to the wavelength of the light source to be used, but is preferably one that does not generate gas during mold pressurization / exposure. When the gas is generated, the mold is contaminated, so that the mold has to be frequently washed, and the resist composition 20 is deformed in the mold, and the transfer pattern accuracy is deteriorated. .

    In the resist composition 20, the polymerizable monomer contained is preferably a radical polymerizable monomer, and the photopolymerization initiator I is preferably a radical polymerization initiator that generates radicals upon light irradiation.

(Other ingredients)
As already described, the resist composition 20 used in the pattern forming method of the present invention is used for various purposes in addition to the above-described polymerizable compound 21, fluorine-containing polymerizable surfactant 22, and photopolymerization initiator I. In addition, other components such as a surfactant, an antioxidant, a solvent, and a polymer component may be included as long as the effects of the present invention are not impaired. The outline of other components will be described below.

-Antioxidant-
The resist composition 20 can contain a known antioxidant. Content of antioxidant is 0.01-10 mass% with respect to a polymerizable monomer, for example, Preferably it is 0.2-5 mass%. When using 2 or more types of antioxidant, the total amount becomes the said range.

The antioxidant suppresses fading caused by heat or light irradiation and fading caused by various oxidizing gases such as ozone, active oxygen, NO _x , SO _x (X is an integer). In particular, in the present invention, by adding an antioxidant, there is an advantage that coloring of a cured film can be prevented and a reduction in film thickness due to decomposition can be reduced. Examples of such antioxidants include hydrazides, hindered amine antioxidants, nitrogen-containing heterocyclic mercapto compounds, thioether antioxidants, hindered phenol antioxidants, ascorbic acids, zinc sulfate, thiocyanates, Examples include thiourea derivatives, sugars, nitrites, sulfites, thiosulfates, hydroxylamine derivatives, and the like. Among these, hindered phenol antioxidants and thioether antioxidants are particularly preferable from the viewpoint of coloring the cured film and reducing the film thickness.

    Commercially available products of the antioxidants include trade names Irganox 1010, 1035, 1076, 1222 (above, manufactured by Ciba Geigy Co., Ltd.), trade names Antigene P, 3C, FR, Sumilyzer S, and Sumilizer GA80 (Sumitomo Chemical Co., Ltd.). Product name) ADK STAB AO70, AO80, AO503 (manufactured by ADEKA Corporation) and the like. These may be used alone or in combination.

-Polymerization inhibitor-
The resist composition 20 preferably contains a small amount of a polymerization inhibitor. As content of a polymerization inhibitor, it is 0.001-1 mass% with respect to all the polymerizable monomers, More preferably, it is 0.005-0.5 mass%, More preferably, it is 0.008-0. By blending an appropriate amount of a polymerization inhibitor of 05% by mass, it is possible to suppress a change in viscosity over time while maintaining high curing sensitivity.

-Solvent-
The resist composition 20 can contain various solvents as required. A preferable solvent is a solvent having a boiling point of 80 to 200 ° C. at normal pressure. Any solvent can be used as long as it can dissolve the composition, but a solvent having any one or more of an ester structure, a ketone structure, a hydroxyl group, and an ether structure is preferable. Specifically, preferred solvents are propylene glycol monomethyl ether acetate, cyclohexanone, 2-heptanone, gamma butyrolactone, propylene glycol monomethyl ether, ethyl lactate alone or a mixed solvent, and a solvent containing propylene glycol monomethyl ether acetate. Most preferable from the viewpoint of coating uniformity.

    The content of the solvent in the resist composition 20 is optimally adjusted according to the viscosity of the components excluding the solvent, the coating property, and the target film thickness, but from the viewpoint of improving the coating property, 0 to 99 mass in the total composition. % Is preferable, and 0 to 97% by mass is more preferable. When forming a pattern with a film thickness of 500 nm or less, 20 to 99% by mass is preferable, 40 to 99% by mass is more preferable, and 70 to 98% by mass is particularly preferable.

-Polymer component-
In the resist composition 20, for the purpose of further increasing the crosslinking density, a polyfunctional oligomer having a molecular weight larger than that of the other polyfunctional polymerizable monomer can be blended within a range that achieves the object of the present invention. . Examples of the polyfunctional oligomer having photoradical polymerizability include various acrylate oligomers such as polyester acrylate, urethane acrylate, polyether acrylate, and epoxy acrylate. The addition amount of the oligomer component is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, further preferably 0 to 10% by mass, and most preferably 0 to 5% by mass with respect to the component excluding the solvent of the composition. %.

    The resist composition 20 may contain a polymer component from the viewpoint of improving dry etching resistance, imprint suitability, curability, and the like. Such a polymer component is preferably a polymer having a polymerizable functional group in the side chain. As a weight average molecular weight of the said polymer component, 2000-100000 are preferable from a compatible viewpoint with a polymerizable monomer, and 5000-50000 are more preferable.

  The addition amount of the polymer component is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, still more preferably 0 to 10% by mass, and most preferably 2% by mass or less, relative to the component excluding the solvent of the composition. It is. From the viewpoint of pattern formation, it is preferable that the content of the polymer component having a molecular weight of 2000 or more is 30% by mass or less in the resist composition 20 except for the solvent. The resin component is preferably as few as possible, and it is preferable that the resin component is not included except for a surfactant and a trace amount of additives.

  In addition to the above-described components, the resist composition 20 may include a release agent, a silane coupling agent, an ultraviolet absorber, a light stabilizer, an anti-aging agent, a plasticizer, an adhesion promoter, a thermal polymerization initiator, Coloring agents, elastomer particles, photoacid growth agents, photobase generators, basic compounds, flow regulators, antifoaming agents, dispersants, and the like may be added.

  The resist composition 20 can be prepared by mixing the above-described components. Moreover, after mixing each component, it can also prepare as a solution by filtering with a filter with the hole diameter of 0.003 micrometer-5.0 micrometers, for example. Mixing and dissolution of the curable composition for photoimprint is usually performed in the range of 0 ° C to 100 ° C. Filtration may be performed in multiple stages or repeated many times. Moreover, the filtered liquid can be refiltered. The material of the filter used for filtration may be polyethylene resin, polypropylene resin, fluorine resin, nylon resin or the like, but is not particularly limited.

    In the resist composition 20, the viscosity at 25 ° C. of the components excluding the solvent is preferably 1 to 100 mPa · s. More preferably, it is 3-50 mPa * s, More preferably, it is 5-30 mPa * s. By setting the viscosity within an appropriate range, the rectangularity of the pattern can be improved and the remaining film can be kept low.

"Pattern substrate manufacturing method"
The resist layer 40 patterned on the substrate 10 by the above method can be used as a mask for patterning the substrate 10 by lithography. In the present embodiment, as shown in FIG. 1F, the surface 10S of the substrate 10 is processed to have a concavo-convex pattern on the substrate 10 using the resist pattern 1 as a mask.

  Although the processing method of the board | substrate 10 is not restrict | limited in particular, It is preferable that it is a method which can be processed with sufficient pattern precision in the substantially perpendicular direction with respect to the substrate surface 10S. Examples of preferable processing methods include a dry etching method and an ion milling method.

  When the concave portion having a desired depth is formed on the substrate 10S (FIG. 1G), the resist layer 40 remaining on the substrate 10S can be removed to obtain the pattern substrate 2. The method for removing the resist layer 40 is not particularly limited, but anisotropic etching using oxygen plasma or the like can be used.

  In the pattern forming method of the present invention, a resist composition 20 containing a polymerizable compound 21, a polymerization initiator I activated by light L1, and a fluorine-containing polymerizable surfactant is formed on a substrate 10 in a plurality of liquids. A resist layer 20m that is discretely arranged as the droplet 20 is formed. Since the resist layer 20m has a low fluorination rate in the resist composition 20, the viscosity of the resist composition 20 and the etching resistance of the resist 40 after curing are suitably maintained, and the polymerizable surfactant 22 is also maintained. As a result, it is possible to improve mold releasability from the mold 30 without promoting pattern formation failure due to uneven distribution of the surfactant or deterioration of the mold (mold) 30.

  Therefore, according to the present invention, in the pattern formation by the imprint method, highly accurate patterning is possible even in the nano-order pattern formation, and the pattern formation excellent in mass productivity and etching resistance can be performed.

  Moreover, the patterned substrate 2 patterned with high precision can be manufactured by processing the board | substrate 10 with a lithography method using the resist pattern 1 made by the pattern formation method of this invention as a mask.

Examples and comparative examples according to the present invention will be described.
Example 1
<Resist application process>
After preparing a Si substrate and cleaning the processed surface with a UV cleaner (treatment time 1 minute), silane coupling agent 3-acryloxypropyltrimethoxysilane (KBM-5103) (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.1 g And an organic solvent, propylene glycol monomethyl ether acetate (PGMEA) 10 g, a surface treatment solution is used to form an adhesive layer with a thickness of 0.1 nm by spin coating, and further at 120 ° C. for 5 minutes. Annealing treatment was performed.

  Next, the resist composition R1A was ejected in accordance with the mold pattern shape by an ink jet method under the following ink jet condition 1 to form a resist layer on the substrate.

<< Resist Composition R1A >>
・ Polymerizable compound (1,4-diacroyloxymethylbenzene, 2′-naphthylmethyl acrylate 49 g each)
・ 1.0 g of fluorine-containing polymerizable surfactant (Ax-2)
Photopolymerization initiator (ethyl-2,4,6-triethylbenzoinphenylphosphinate) (Irgacure 379, manufactured by BASF) 1.0 g
(Inkjet condition 1)
Printer: DMP2831 (Fujifilm Dimatix)
Head: Dedicated head discharge condition with 10 pl nozzle: Waveform adjustment was performed so that the discharge amount was 6 pl.
Drawing pattern: Droplets (corresponding to 20 m) were arranged at the intersections of the 450 μm pitch grid pattern.

<Imprint process>
Concentric stripes on the surface have a 90 nm pitch (projection 50 nm width, depth 65 nm, taper angle 83 °, radial direction (1) 22 mm to 32 mm (10 mm width band), (2) 19 mm to 18 mm (1 mm) Width band), (3) 14.9 mm to 15.0 mm (1 mm width band), (4) 12.01 to 12.00 mm (0.01 mm width band), (1) to (4) in four areas Prepare a quartz mold structure with a 2.5-inch disk with a concavo-convex pattern arranged in a line, and release it using the fluorine antifouling coating agent OPTOOL DSX (manufactured by Daikin Industries) on the concavo-convex pattern surface. Treated.

After pressing the concavo-convex surface of the mold structure against the Si substrate on which the resist layer is formed in a helium atmosphere in a chamber, the surface of the mold structure is uniformly applied under conditions of room temperature and 10 atm. By applying pressure for 60 seconds, the uneven pattern formed on the mold structure was transferred to the resist layer. In this state, 300 mJ / cm ² was irradiated from the mold structure side by UV irradiation (wavelength 365) nm to cure the resist and fix the patterned shape. A pattern forming body in which a resist layer to which the pattern was transferred was formed was produced.

<Pattern formation process>
For a pattern formed body on which a resist layer having a concavo-convex pattern transferred is formed, using an imprint resist layer to which the concavo-convex pattern is transferred as a mask, an argon ion milling method (ULVAC) is applied to a substrate cooled to 10 ° C. from the back side. Dry etching was performed with an ICP etching apparatus NE-550 manufactured by the company, and a concavo-convex shape based on the concavo-convex pattern shape formed in the resist layer was formed on the substrate.

<Resist layer peeling process>
Thereafter, oxygen ashing treatment was performed on the surface of the pattern forming body on which the concavo-convex shape was formed, and further the UV treatment was performed to remove the resist layer remaining after the substrate processing.

(Comparative Example 1)
A resist composition R1B is prepared with the following composition, and the resist composition is applied by a spin coating method so that the thickness after baking is 40 nm, and further baked (60 ° C., 1 minute). Mask pattern formation and substrate processing were performed in the same manner as in Example 1 except that the resist layer was formed.

<< Resist Composition R1B >>
・ Polymerizable compound (1,4-diacroyloxymethylbenzene, 2'-naphthylmethyl acrylate 20 g each)
・ 1.0 g of fluorine-containing polymerizable surfactant (Ax-2)
Photopolymerization initiator (ethyl-2,4,6-triethylbenzoinphenylphosphinate) (Irgacure 379, manufactured by BASF) 0.8 g
・ Organic solvent (PGMEA: solid content concentration 4%) 959.0 g
(Comparative Example 2)
Mask pattern formation and substrate processing were performed in the same manner as in Comparative Example 1 except that a fluorine-containing surfactant having no polymerizability (PF656) manufactured by Polyfox Co., Ltd. was used as the surfactant.

(Comparative Example 3)
Mask pattern formation and substrate processing were performed in the same manner as in Comparative Example 1 except that the surfactant was not included in the resist composition.

(Comparative Example 4)
A mask pattern was formed and the substrate was processed in the same manner as in Example 1 except that a fluorine-containing surfactant having no polymerizability (PF656) manufactured by Polyfox Co., Ltd. was used as the surfactant.

(Comparative Example 5)
Mask pattern formation and substrate processing were performed in the same manner as in Example 1 except that the surfactant was not added to the resist composition.

(Example 2)
Mask pattern formation and substrate processing were performed in the same manner as in Example 1 except that an aliphatic polyfunctional monomer was used as the polymerizable compound of the resist composition.
The components of the used resist composition R2 are as follows.
<< Resist Composition R2 >>
Polymerizable compound (TPGDA: tripropylene glycol diacrylate (Aronix M220 (manufactured by Toagosei Co., Ltd.))) 98.0 g
・ 1.0 g of fluorine-containing polymerizable surfactant (Ax-2)
Photopolymerization initiator (ethyl-2,4,6-triethylbenzoinphenylphosphinate) (Irgacure 379, manufactured by BASF) 1.0 g
(Comparative Example 6)
Mask pattern formation and substrate processing were performed in the same manner as in Example 2 except that a fluorine-containing surfactant having no polymerizability (PF656) manufactured by Polyfox Co., Ltd. was used as the surfactant.

(Comparative Example 7)
Mask pattern formation and substrate processing were performed in the same manner as in Example 2 except that the surfactant was not added to the resist composition.

(Comparative Example 8)
A mask similar to Example 2 except that a fluorine-containing resin (polymer of the following fluorene prepolymer M01, polymerization degree 200 to 400) was used as the polymerizable compound in the resist composition, and no surfactant was used. Pattern formation and substrate processing were performed.

(Fluorene prepolymer)
Isophorone diisocyanate (58 g), 2-hydroxyethyl acrylate (39 g), p-methoxyphenol (0.02 g), and dibutyltin dilaurate (0.005 g) are placed in a 500 ml glass reaction vessel so that the temperature in the reaction vessel reaches 70 ° C or lower. Stirring well while adjusting, a monomer having an isocyanate group was obtained. Subsequently, 161 g of a fluoropolymer having a hydroxyl group (manufactured by Asahi Glass Co., Ltd., Lumiflon LF910LM) was added to the reaction vessel, maintained at 80 to 90 ° C. with good stirring, and 0.02 g of dibutyltin dilaurate was added. An anti-content was produced to obtain a fluoroprepolymer M01 (fluorine content: 41 wt.%).

(Comparative Example 9)
Mask pattern formation was carried out in the same manner as in Example 2 except that a fluorine-containing resin (the above-mentioned fluorene prepolymer M01) was used as the polymerizable compound in the resist composition and no surfactant (fluorine-containing polymerizable compound) was used. Then, the substrate was processed.

<Evaluation>
About the said Example and comparative example, evaluation at the time of resist application | coating, mold mold release property, the shape and residual film thickness of a resist pattern, repeated pattern formation (50 times) characteristic deterioration, the shape and quality at the time of a board | substrate process are as follows. did. The results are shown in Table 1 together with the liquid properties.

<< Performance at resist application >>
The film formability was evaluated according to the following criteria.
・ Spin coating method: possible film formation ○
No film formation ×
・ Inkjet method: Good ejection performance (no ejection, landing position deviation ≦ 25μm) ○
Discharge is not good, but pattern can be formed
(No ejection, 100 μm> Landing position deviation> 25 μm)
Non-ejection (5% or less of nozzle)
And landing position deviation of 100 μm or more occurs ×
Non-ejection (at 5% or more of nozzles) XX

<< Mold releasability >>
The releasability was evaluated using the degree of moge and line breakage as an index.
・ Pattern defects such as pattern baldness and broken lines during mold release are less than 1% of the total.
Pattern defects such as pattern baldness and broken lines at the time of mold release exceed 1%
<< Resist pattern shape and residual film thickness >>
The pattern height was compared with the mold depth and used as an index for pattern formation.
・ Pattern shape: The difference between the height of the convex part (depth of the concave part) and the mold is less than ± 5%.
The difference between the height of the convex part (depth of the concave part) and the mold is ± 5 to 10%.
The difference between the height of the convex part (depth of the concave part) and the mold exceeds ± 10%.
・ Inkjet placement pattern defects:
When the sample after imprinting was observed with an optical microscope, the presence or absence of defects or foreign matters that occurred at a frequency corresponding to the droplet arrangement pattern of the ink jet was evaluated as an index of the ink jet arrangement pattern defect.
No defects ○ (0.1% or less)
Defective ×
-Residual film thickness: About the band of each band (1)-(4), the value of residual film thickness was calculated | required from the cross-section SEM of the shape after the imprint in a center part. Further, the film thicknesses in the four directions of the obtained bands were obtained, and the PV values grasped from the data were evaluated based on the following criteria.

Shape accuracy: ○ PV value is 8nm or less Distribution is within allowable range
△ PV value is 8nm ~ 12nm
× PV value is 12nm or more Distribution is out of tolerance

<< Repetitive pattern formation (50 times) characteristic deterioration evaluation >>
The mold after imprinting 50 times repeatedly under the same conditions was used to evaluate the releasability and mold contamination when the 51st sample was created using the following indices.

・ The releasability was evaluated using the degree of baldness and line breakage as an index.
Less than 1% of pattern defects such as pattern baldness and line breaks during mold release ○
Pattern defects such as pattern baldness and broken lines at the time of mold release exceed 1%
-Mold contamination due to accumulation of deposits on the mold was evaluated using the degree of deterioration of the imprint pattern height caused by the contamination as an index.
Deterioration of pattern convex height due to accumulation of mold dirt is less than 5% ○
Deterioration of pattern height due to accumulation of mold dirt is 5-10% △
Deterioration of pattern protrusion height due to accumulation of mold stains exceeds 10% ×

<< Shape and quality during substrate processing >>
-Substrate processability during RIE dry etching:
The difference between the convex height and the target height is less than ± 5%, and the roughness is the same as the mold but smaller than the mold ○
The difference between the height of the convex part and the target height is ± 5 to 10%, or the roughness is larger than the roughness of the mold and smaller than plus 1 nm.
The difference between the height of the convex part and the target height exceeds ± 10%, or the roughness is 1 nm or more larger than the roughness of the mold.

<< Repetitive pattern formation (50 times) characteristic deterioration evaluation >>
Using the mold after imprinting 50 times repeatedly under the same conditions, the shape of the imprint sample when the 51st sample was created, and the substrate processed by etching using the created imprint sample in the same manner The shape of was evaluated.

・ Pattern shape: The difference between the height of the convex part (depth of the concave part) and the mold is less than ± 5%.
The difference between the height of the convex part (depth of the concave part) and the mold is ± 5 to 10%.
The difference between the height of the convex part (depth of the concave part) and the mold exceeds ± 10%.
-Substrate processability during RIE dry etching:
The difference between the convex height and the target height is less than ± 5%, and the roughness is the same as the mold but smaller than the mold ○
The difference between the height of the convex part and the target height is ± 5 to 10%, or the roughness is larger than the roughness of the mold and smaller than plus 1 nm.
The difference between the height of the convex part and the target height exceeds ± 10%, or the roughness is 1 nm or more larger than the roughness of the mold.

<< Liquid properties >>
The viscosity was measured at 25 ° C. using Rotovisco RV1 (manufactured by HAAKE).

As shown in Table 1, the effect of the present invention was confirmed.

  The present invention can be preferably applied to patterning of patterned media and semiconductor element substrates.

DESCRIPTION OF SYMBOLS 1 Resist pattern 2 Pattern substrate 10 Substrate 10S Substrate surface 20 Resist composition, droplet 20m Resist layer 21 Polymerizable compound 22 Fluorine-containing polymerizable surfactant 30 Mold (mold)
40 Cured resist layer L1 Light (electron beam) protective film

Claims (9)

On the board
Forming a resist layer in which a resist composition including a polymerizable compound, a polymerization initiator activated by light or electron beam, and a fluorine-containing polymerizable surfactant is discretely arranged as a plurality of droplets. ,
The resist layer is pressed against the surface of the mold having a predetermined uneven pattern on the surface,
Irradiating the resist layer with the light or electron beam to cure the resist layer,
A pattern forming method, wherein the mold is peeled from the resist layer.   The pattern forming method according to claim 1, wherein the content of the polymerizable surfactant in the resist composition is 5% by mass or less.   As the polymerizable surfactant, a fluorine-containing polymerizable compound containing at least one fluorine-containing group selected from a fluoroalkyl group and a fluoroalkyl ether group in the monomer of the polymerizable surfactant is used. The pattern forming method according to claim 1 or 2, characterized in that:   As the polymerizable surfactant, the monomer of the polymerizable surfactant has a plurality of at least one fluorine-containing group selected from a fluoroalkyl group and a fluoroalkyl ether group, and the plurality of fluorine-containing groups The pattern forming method according to claim 3, wherein a fluorine-containing polymerizable compound in which at least two of the groups are separated by a linking group having 2 or more carbon atoms is used.   The pattern forming method according to claim 4, wherein at least two of the fluorine-containing groups are fluoroalkyl groups having 2 or more carbon atoms.   The pattern forming method according to claim 1, wherein the polymerizable compound includes a monomer having at least one aromatic group.   The pattern forming method according to claim 1, wherein a polyfunctional monomer that is crosslinked by polymerization to become a polymer having a three-dimensional structure is used as the polymerizable compound.   The cross-linking agent that cross-links the surface and the resist layer is applied to the surface of the substrate on which the resist layer is disposed before the resist layer is disposed on the substrate. The pattern formation method in any one of 1-7.   An uneven pattern based on the pattern of the resist layer is formed on the substrate surface by lithography using a resist layer patterned on the substrate by the pattern forming method according to claim 1 as a mask. A pattern substrate manufacturing method comprising forming the pattern substrate.

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