JP2010152013A - Pattern forming method, imprint mold, and method for manufacturing magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method which can design a track width optimally according to a shape of a recording head or the like. <P>SOLUTION: The pattern forming method includes a step of forming a composition film containing a diblock copolymer on a substrate, a step of phase-separating the composition film containing the diblock copolymer into a cylinder shape or a lamellar shape in a first direction to form an easy etching area containing a first phase component extending in the first direction, a step of forming a resist film on the phase-separated composition film containing the diblock copolymer, a step of forming a pattern extending in a second direction that intersects with the first direction on the resist film by electron beam drawing or light exposure, and a step of etching the substrate using the resist film where the pattern is formed by the electron beam or light exposure and an etching-resistant pattern containing a second phase component as a mask. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pattern forming method, an imprint mold manufactured by the pattern forming method, and a method of manufacturing a magnetic recording medium using the imprint mold.

  Since the invention of the magnetic recording apparatus, the recording density has been increasing year by year, and the recording density continues to increase even now.

  Patterned media is an effective means for realizing a terabit-class recording density, but in order to achieve such a high recording density, a required cell size is as fine as 30 to 20 nm or less. Although microfabrication is possible by drawing a fine pattern with an electron beam, this takes a long time. Therefore, the processed medium is very expensive.

  It has been proposed that this problem can be solved by producing patterned media using phase separation of diblock copolymers (for example, see Non-Patent Document 1 and Patent Document 1). Specifically, for example, a diblock copolymer of polystyrene and polymethylmethacrylate is phase-separated to form a dot pattern, and the dot pattern is transferred to the magnetic film to form a magnetic dot used as a recording cell. Due to the phase separation of the diblock copolymer, a circular dot pattern is formed in a close packed arrangement.

In a magnetic recording apparatus equipped with a patterned medium, there is a possibility that writing or reading is performed across two or more recording cells by a recording head. This can be avoided if conditions such as the arrangement of magnetic dots and the track width can be optimized according to the recording head. It has been proposed to form a bit shape that follows a head shape locus by forming a dot pattern by phase-separating a diblock copolymer (see, for example, Patent Document 2). However, in the method of forming a dot pattern by phase-separating diblock copolymers, it is difficult to optimize conditions such as the arrangement of magnetic dots and the track width according to the shape of the recording head.
K. Naito et al., IEEE Trans. Magn., Vol. 38, p. 1949 JP 2004-342226 A JP 2004-265474 A

  An object of the present invention is to provide a pattern forming method having a high degree of freedom in which a track width or the like can be optimally designed according to the shape of a recording head or the like.

  The pattern forming method according to one embodiment of the present invention includes a composition containing a diblock copolymer on a substrate, and includes a first phase and a second phase having higher etching resistance than the first phase. A step of forming a composition film to be separated; and a component of the first phase extending in the first direction by phase-separating the composition film containing the diblock copolymer into a cylindrical shape or a lamellar shape in the first direction. A step of forming an easy-etching region comprising: a step of forming a resist film on the composition film containing the phase-separated diblock copolymer; and the resist film by electron beam drawing or light exposure. A step of forming a pattern extending in a second direction intersecting the first direction, a resist film patterned by electron beam or light exposure, and an etching resistant pattern including the component of the second phase Characterized by comprising the step of etching the substrate as a disk.

  A pattern forming method according to another aspect of the present invention includes a composition comprising a diblock copolymer on a substrate, and includes a first phase and a second phase having higher etching resistance than the first phase. A step of forming a composition film for phase separation; and a phase separation of the composition film containing the diblock copolymer in a cylinder or a lamellar shape in a first direction, and a first phase extending in the first direction. Forming an easy-etching region containing a component; and removing the easy-etching region containing the first phase component from the composition film to include the second phase component extending in the first direction. A step of forming an etching resistant pattern; a step of forming a resist film on the etching resistant pattern; and a second direction intersecting the first direction on the resist film by electron beam drawing or light exposure. Extending And a step of etching the substrate using a resist film patterned by electron beam or light exposure and an etching resistant pattern including the second phase component as a mask. To do.

  The imprint mold which concerns on 1 aspect of this invention comprises the board | substrate which has the grid | lattice pattern processed by said pattern formation method.

  The method for manufacturing a magnetic recording medium according to one aspect of the present invention is directed to the step of forming a magnetic film on a body substrate, the step of forming a resist film on the magnetic film, and the resist film. Imprinting using the imprint mold having the grid pattern described in (2), forming a grid-shaped recess in the resist film, thereby obtaining a resist pattern consisting of projections, and using the resist pattern as a mask Etching the magnetic film to form a magnetic film pattern separated by lattice-like grooves.

  According to the present invention, there is provided a pattern forming method having a high degree of freedom capable of optimally designing a track width or the like according to the shape of a recording head or the like.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1A is a plan view of a magnetic recording medium manufactured by a method according to an embodiment of the present invention. As shown in the figure, the magnetic recording medium 1 is provided with tracks 2 concentrically. An enlarged view of region A in FIG. 1A is shown in FIG. As shown in the figure, in the track 2, the magnetic cells 3 are arranged in parallel at the same pitch on the inner track and the outer track. This magnetic recording medium is manufactured using an imprint mold according to an embodiment of the present invention. This imprint mold can be manufactured by the pattern formation method which concerns on one Embodiment of this invention.

  First, a composition film containing a diblock copolymer used in the pattern forming method according to an embodiment of the present invention will be described.

  The composition film containing the diblock copolymer separates into two phases having different etching resistances. The composition and molecular weight of the diblock copolymer component are not particularly limited as long as the phase-separated first phase component satisfies the condition that the etching resistance is lower than that of the second phase component. Examples of the diblock copolymer containing the first phase component and the second phase component include polystyrene-polymethyl methacrylate (PS-PMMA), polystyrene-poly (ethylene-alt-propylene) (PS-PEP), Examples include polystyrene-polybutadiene (PS-PBD), polystyrene-polyisoprene (PS-PI), polystyrene-polyvinyl methyl ether (PS-PVME), and polystyrene-polyethylene oxide (PS-PEO).

  Examples of the diblock copolymer having a high cylinder orientation include a diblock copolymer of a polyacrylate substituted with a liquid crystalline mesogenic group and polyethylene oxide, polypropylene oxide, polybutylene oxide, or the like.

  By adjusting the total molecular weight of the diblock copolymer, the molecular weight of each polymer component, the difference in polarity, and the like, the phase separation pitch obtained can be controlled.

  FIG. 2 is an example of a phase diagram showing the composition range in which the diblock copolymer phase separates into cylinders or lamellae. In FIG. 2, χ is a Flory-Huggins inter-segment interaction parameter determined by the polymer component, N is the degree of polymerization of the entire diblock copolymer, and f is the composition ratio of the two polymer chains constituting the diblock copolymer. is there. Moreover, the schematic diagram of each phase-separation state is shown.

  As shown in FIG. 2, it is preferable that the composition ratio of two polymer chains is approximately 0.3 to 0.7 in order to constitute a lamella, and in order to constitute a cylinder, a polymer chain that becomes a cylinder. It is preferable that the composition ratio is about 0.15 to 0.35. When mixing other components with the block copolymer component, it is preferable to adjust the mixing amount so that the volume of each phase when the phases are separated is the above ratio.

As a method of imparting a difference in etching resistance between the first phase and the second phase having a phase-separated structure, it is preferable that the second phase component contains a silicon-containing component having high oxygen etching resistance. For example, derivatives such as cissesquioxane can be effectively used (for example, Nano Letters, (2004) 273; Appl. Phys. Lett., 88, 243107 (2006)). Further, silicates represented by the following general formula (1), hydrogen siloxane represented by the general formula (2), methyl siloxane represented by the general formula (3), and methyl siloxane represented by the general formula (4) Organic or inorganic silicon-containing compounds can be used. Furthermore, hydrogen silsesquioxane represented by the following general formula (5), methyl silsesquioxane represented by the general formula (6), and the like can also be used.

  A pattern forming method according to an embodiment of the present invention will be described with reference to FIGS. In this description, the cylinder portion is an easy etching layer, but the etching difficulty of the phase structure may be reversed. First, as shown in FIG. 3, a composition film 12 containing a diblock copolymer is formed on a substrate 11. The board | substrate 11 is not specifically limited, For example, a plastic substrate, a glass substrate, a silicon substrate etc. can be used. A thin film made of a magnetic material, a semiconductor, an insulating film, a conductive film, or the like may be formed on the substrate 11. That is, the substrate 11 can be directly processed by the pattern forming method according to the embodiment of the present invention. Alternatively, a pattern can be formed on the thin film formed on the substrate 11 by the method according to the embodiment of the present invention.

  The composition film 12 containing the diblock copolymer is annealed in a heat or solvent atmosphere to obtain a composition film 13 containing the phase-separated diblock copolymer as shown in FIG. By the phase separation, the first polymer component forms a cylindrical easy-to-etch region 14. The cylindrical easy-etch region 14 extends in the first direction.

  In the composition film 13 containing the phase-separated diblock copolymer, it is desirable that the directions of the cylinders constituting the easy-etching region 14 are aligned in a predetermined direction. For example, as shown in FIG. 5, this can be achieved by pre-forming guides 20 on opposite sides of the substrate 11. A composition film 12 containing a diblock copolymer as shown in FIG. 6 is formed between the guides 20 to obtain a composition film 13 containing a phase-separated diblock copolymer as shown in FIG. (For example, T. Yamaguchi, et al., J. Photopolym. Sci. Technol., 18 (2005) pp. 421; D. Sundrani et al., Langmuir 20, pp. 5091).

  In this case, the pattern serving as a guide in the phase separation direction does not need to have a physically uneven shape, for example, by forming an alignment pattern with a composition having a different surface energy, or by optical or / and chemical treatment. In addition, pattern formation by surface treatment having affinity for one composition of the block copolymer may be performed (for example, MP Stoykovich, et al., Science 308 (2005) pp. 1442; KO Stuen, I. In, E. Han, JA Streifer; RJ Hamers, PF Nealey, P. Gopalan, Journal of Vacuum Science and Technology B, 25, (2007) pp. 1958-1962).

  Alternatively, the composition film 13 containing the phase-separated diblock copolymer can be obtained by applying a shear stress along the surface of the composition film 12 containing the diblock copolymer (DE Angelescu et al., Adv Mater., 16 (2004) pp. 1739). When the produced phase separation template is used for forming a magnetic medium, it is desirable that the guide or shear stress direction follows the arm trajectory of the head.

  Next, the easy-etching region 14 including the first phase component is removed to form an etching resistant pattern 15 including the second phase component as shown in FIG. The easy etching region 14 can be removed by, for example, plasma treatment, heat treatment, or the like.

  Further, as shown in FIG. 9, a resist film 16 for forming a pattern crossing the phase separation pattern of the diblock copolymer is formed on the etching resistant pattern 15. At this time, in order to prevent pattern shape deterioration due to mixing, it is desirable to take measures to reduce mutual solubility between the photoresist film 16 and the etching resistant pattern 15. Specifically, this can be made possible by insolubilization of the diblock copolymer component or additive component by three-dimensional crosslinking. Alternatively, a photoresist having a polarity different from that of the diblock copolymer component may be used.

  The resist film 16 is subjected to direct drawing by EB or laser, or pattern exposure by a mask exposure apparatus. The drawing pattern or the mask pattern for mask exposure at this time extends in a second direction that substantially intersects the first direction. At this time, a pattern indicating information necessary for a recording medium such as a servo mark may be included as a part of the pattern of drawing or mask exposure.

  Examples of the pattern forming method include direct drawing with EB or laser, and pattern exposure with a light source such as a mercury lamp, KrF excimer laser, ArF excimer laser, EUV, and X-ray through a photomask. It is not limited to.

  Also, it is preferable to use resists suitable for each exposure light source for the pattern formation.

  After the patterning exposure, the photoresist film is subjected to a heat treatment as necessary, and the photoresist film is developed with a developing solution to expose the etching resistant pattern 15 including the component of the second phase as shown in FIG. Let As shown in the drawing, the pattern 19 of the photoresist film 16 extending in the second direction is left on the etching resistant pattern 15 extending in the first direction.

  Next, the substrate 11 is etched using the etching resistant pattern 15 including the component of the second phase and the pattern 19 of the photoresist film 16 as a mask to form a groove 21 as shown in FIG.

  Finally, the etching resistant pattern 15 including the second phase component and the pattern 19 of the photoresist film 16 are removed, and an imprint mold having a grid-like convex portion surrounding the rectangular groove 21 as shown in FIG. 30 is formed.

  An example in which a lattice pattern is formed on a silicon substrate by the above-described method using a composition obtained by mixing SOG (spin-on-glass) with polystyrene-polyethylene oxide (PS-PEO) as a diblock copolymer will be described.

  As shown in FIG. 3, a solution obtained by mixing SOG with polystyrene-polyethylene oxide (PS-PEO) is applied onto a silicon substrate as the substrate 11 to form a diblock copolymer composed of a mixture of PS-PEO and SOG. The containing composition film 12 is formed. The first phase component is PS and the second phase component is PEO. By blending SOG which is a silicon-containing component, the oxygen etching resistance of the second phase component is higher than the PS of the first phase component.

  An annealing treatment is performed to obtain a composition film containing the phase-separated diblock copolymer. As an annealing method at this time, any method such as heating or exposure in a solvent atmosphere may be used. As a result, as shown in FIG. 4, the easy-etching region 14 made of PS, which is the first phase component, is formed in a cylindrical shape, and the composition film 13 containing the phase-separated diblock copolymer is obtained. . The easy etching region 14 extends in the first direction.

  The easy-etching region 14 is removed to obtain an etching-resistant pattern 15 including a second phase component as shown in FIG. The easy-etching region 14 can be removed by heating at 300 ° C. or higher, for example. Alternatively, the easy etching region 14 may be removed using oxygen plasma treatment or the like.

  A photoresist film 16 is formed on the etching resistant pattern 15 as shown in FIG. A pattern is drawn on the photoresist film 16 by an EB drawing apparatus. The pattern formed on the photoresist film 16 extends in a second direction that intersects the first direction. The angle formed by the first direction and the second direction can be set in the range of about 60 ° to 90 °, for example, depending on the shape of the recording head.

  After the resist development, as shown in FIG. 10, a lattice-like etching mask is formed by the etching resistant pattern 15 including the component of the second phase and the pattern 19 of the photoresist film.

Etching is performed using the obtained lattice pattern as a mask to process the substrate 11 as shown in FIG. As the etching gas, preferably compositions selective ratio of the etching rate is made large between the mask and the substrate, if the substrate 11 is a silicon substrate, can be used, for example SF _6. Furthermore, SF ₆ and a mixed gas such as oxygen, nitrogen, or a chlorine-based gas may be used, but the present invention is not limited to these.

  After the substrate 11 is etched, the etching resistant pattern 15 and the photoresist film pattern 19 are peeled off by wet etching with a solvent, hydrofluoric acid, or the like, or dry etching with a halogen-based gas, and the like, and a rectangular groove 21 as shown in FIG. A silicon substrate is obtained. Since the aspect ratio of the aspect ratio of the rectangular pattern is defined by the phase separation pitch of the diblock copolymer composition and the width of the pattern 19 of the photoresist film, the selection of the diblock copolymer composition and the design of the pattern 19 shown in FIG. It is also possible to form a concave pattern having an arbitrary aspect ratio.

  The easily etched region 14 constituted by the phase-separated first phase components may be lamellar. That is, the first and second phase components are layered and phase-separated in a direction perpendicular to the substrate, and the first phase component and the second phase component are alternately arranged on the substrate. It is preferable.

  An example using such phase separation will be described with reference to FIGS. An imprint mold can be formed by the same method as in the case of cylindrical phase separation, except that a diblock copolymer composition having a composition that phase-separates into a lamellar shape is used. For example, lamellar phase separation can be obtained by changing the composition ratio of the polymer component of the diblock copolymer or the content ratio of the silicon compound contained in the diblock copolymer.

  First, as shown in FIG. 3, a composition film 12 containing a diblock copolymer is formed on a substrate 11. Prior to the formation of the composition film 12 containing the diblock copolymer, a thin film made of a predetermined random copolymer is formed on the substrate 11 to ensure phase separation perpendicular to the substrate surface. Specifically, it is a thin film of a random copolymer containing first and second components similar to the diblock copolymer used. Moreover, when forming a guide for promoting the phase separation structure arrangement, it is preferable to use a material having an affinity for one composition of the diblock copolymer.

  The composition film 12 containing the diblock copolymer is annealed in a heat or solvent atmosphere to obtain the composition film 13 containing the phase-separated diblock copolymer as shown in FIG. Due to the phase separation, the first phase component forms a lamellar easy-to-etch region 14. As in the case of the cylinder shape, the lamellar easy etching region 14 extends in the first direction.

  The easy-etching region 14 composed of the composition component of the first phase is removed to obtain an etching resistant pattern 15 including the component of the second phase as shown in FIG. On this, a photoresist film 16 is formed as shown in FIG. As shown in FIG. 16, a pattern 19 of the photoresist film 16 is formed by EB drawing and subsequent development processing.

  The substrate 11 is processed as shown in FIG. 11 using the etching resistant pattern 15 including the composition component of the second phase and the pattern 19 of the photoresist film 16 as a mask. Finally, the etching resistant pattern 15 and the pattern 19 of the photoresist film 16 are removed, and an imprint mold 30 as shown in FIG. 12 is formed.

  The easy etching region 14 generated by the phase separation does not necessarily need to be removed from the phase separated diblock copolymer film 13 before the photoresist film 16 is formed.

  As shown in FIG. 17, a photoresist film 16 can be provided on the diblock copolymer composition layer 13 in which a cylindrical easy-etching region 14 is generated and phase-separated. As shown in FIG. 18, a pattern is formed on the photoresist film 16 by EB drawing. Using the photoresist film 16 as a mask, the easily-etched region 14 made of the first phase component in the lower layer is removed. As a result, the etching resistant pattern 15 including the composition component of the second phase as shown in FIG. 10 is obtained, and the pattern 19 of the photoresist film is left on the pattern 15. The substrate 11 is processed as shown in FIG. 11 using the etching resistant pattern 15 including the composition component of the second phase and the pattern 19 of the photoresist film 16 as a mask. Finally, the etching-resistant pattern 15 and the photoresist film pattern 19 are removed to form an imprint mold 30 as shown in FIG.

  A photoresist film 16 can also be provided on the composition film 13 containing the diblock copolymer phase-separated by the generation of the lamellar easy-etching region 14 as shown in FIG. A pattern 19 is formed on the photoresist film 16 by electron beam or light exposure and development as shown in FIG. Further, the easy-etching region 14 made of the first phase component is removed from the exposed lower layer. As a result, the etching resistant pattern 15 including the composition component of the second phase as shown in FIG. 10 is obtained, and the photoresist film pattern 19 is left on the etching resistant pattern 15. The substrate 11 is processed as shown in FIG. 11 using the etching resistant pattern 15 including the composition component of the second phase and the pattern 19 of the photoresist film 16 as a mask. Finally, the etching-resistant pattern 15 and the photoresist film pattern 19 are removed to form an imprint mold 30 as shown in FIG.

  The imprint mold produced by the method according to the embodiment of the present invention is suitably used for manufacturing a magnetic recording medium.

  A method for manufacturing a magnetic recording medium according to an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 21, a magnetic film 32 and an imprint resist film 33 are formed on a medium substrate 31, and the imprint mold 30 produced as described above is disposed. The magnetic film 32 can be formed by, for example, a sputtering method, and the imprint resist film 33 can be formed by, for example, a coating method.

  The imprint mold 30 is pressed as shown in FIG. 22 with a press or the like to form a convex pattern 34 on the imprint resist film 33 as shown in FIG. At this time, the imprint mold 30 may be subjected to a release treatment with a fluorinated alkylsilane coupling agent, a perfluoropolyether derivative, a carbon film, or the like in order to improve release properties.

  The resist residue in the recesses is removed to expose the magnetic film 32 as shown in FIG. 24, and the magnetic film 32 is processed by ion milling or the like. As a result, the divided fine magnetic dots 35 as shown in FIG. 25 can be obtained. The resist pattern 34 on the magnetic dots 35 may be peeled off as shown in FIG. 26 if necessary.

  The recording cell formed of the formed magnetic dots can be formed into a rod shape having different aspect ratios as shown in FIG. 26, for example. As described above, it is difficult to form the rod-shaped nanopattern only by using the phase separation of the diblock copolymer. However, according to the method of the present invention, an optimum pattern can be designed with a high degree of freedom. it can.

  This method can be applied not only to magnetic recording media but also to fields that require the formation of fine patterns, such as optical disks and semiconductor devices.

  Specific examples of the present invention are shown below, but the present invention is not limited to these specific examples.

  Compositions A, B, and C are shown as preparation examples of the solution for forming a self-assembled pattern used in the examples, but are not limited thereto.

  (A) A coating solution was prepared using polystyrene-polyethylene oxide (Mn: PS = 3000, PEO = 3000) and SOG (Tokyo Ohka OCD T-7). The solid component of OCD T-7 was mixed so as to be 3.2 times by weight of PEO, and prepared with a diethylene glycol dimethyl ether solvent so that the total solid component amount in the coating solution was 1.5%.

  (B) A coating solution was prepared using polystyrene-polyethylene oxide (Mn: PS = 3000, PEO = 3000) and SOG (Tokyo Ohka OCD T-7). The solid component of OCD T-7 was mixed so as to be 3.2 times by weight of PEO, and prepared with a triethylene glycol dimethyl ether solvent so that the total solid component amount in the coating solution was 2.5%.

  (C) A coating solution was prepared using polystyrene-polyethylene oxide (Mn: PS = 19000, PEO = 6400) and SOG (Tokyo Ohka OCD T-7). The solid component of OCD T-7 was mixed so as to be 3.8 times the weight of PEO, and prepared with a triethylene glycol dimethyl ether solvent so that the total solid component amount in the coating solution was 2.5%.

  (D) A coating solution was prepared using polystyrene-polyethylene oxide (Mn: PS = 3000, POE = 3000) and SOG (Tokyo Ohka OCD T-7). The mixture was mixed so that the solid component amount of OCD T-7 was 2 times the weight of PEO, and adjusted with triethylene glycol dimethyl ether so that the total solid component amount in the coating solution was 2.5%.

  (D) Polystyrene-polydimethylsiloxane (Mn = 45500, polydimethylsiloxane volume ratio 33.5%) was dissolved in toluene to prepare a coating solution so that the total amount of solid components was 1%.

Example 1
First, a guide 20 (width: 300 nm, height: 10 nm) is formed by drawing hydrogen silsesquioxane (HSQ) on a 3-inch substrate to prepare a substrate 11 as shown in FIG. did.

  The above-described coating solution A was spin-coated on the substrate 11 on which the guide 20 was formed to form the diblock copolymer film 12 as shown in FIG. By annealing at 200 ° C. for 3 hours, as shown in FIG. 7, a diblock copolymer film 13 in which PS formed a cylindrical easy etching region 14 and phase-separated was obtained. The cylinder pitch produced by the phase separation was 16 nm.

  A novolac-based i-line resist film as a photoresist film 16 was formed on the phase-separated diblock copolymer film 13. After pattern exposure by stepper exposure, development is performed with a 2.38% aqueous solution of TMAH, and a 300 nm line extending in a second direction that forms an angle of 90 ° with respect to the first direction in which the easy-etching region 14 extends. A 500 nm space pattern was obtained.

When the silicon substrate was etched with SF ₆ gas using this lattice pattern as a mask, grooves 21 were formed in the substrate 11 as shown in FIG. Thereafter, the etching resistance pattern 15 and the pattern 19 of the photoresist film were removed by performing oxygen etching and cleaning with dilute hydrofluoric acid. As shown in FIG. 12, grooves 21 having a pitch of 16 nm × 800 nm were confirmed on the surface of the silicon substrate 11. This silicon substrate can be used as an imprint mold.

(Example 2)
A substrate 11 having a guide 20 similar to that in Example 1 was prepared, and the coating solution A described above was spin coated to form a diblock copolymer film 12 as shown in FIG. By annealing this at 200 ° C. for 3 hours, as shown in FIG. 7, a diblock copolymer film 13 in which PS formed a cylindrical easy etching region 14 and phase-separated was obtained. The cylinder pitch produced by the phase separation was 16 nm.

  Oxygen etching treatment was performed to remove the easy-etching region 14 made of PS from the phase-separated diblock copolymer film 13 to obtain an etching resistant pattern 15 as shown in FIG. This etching resistant pattern 15 is formed from a mixed phase of PEO and SOG.

  On the etching resistant pattern 15, an 80 nm film of ZEP520 (manufactured by Zeon Corporation) was formed as a photoresist film 16 as shown in FIG. A pattern was drawn with an EB exposure apparatus and developed with IPA to form a pattern 19 of a photoresist film having a 50 nm line and a 100 nm space. As a result, as shown in FIG. 10, a lattice-like pattern composed of the etching-resistant pattern 15 and the photoresist film pattern 19 was obtained.

When the silicon substrate was etched with SF ₆ gas using this lattice pattern as a mask, grooves 21 were formed in the substrate 11 as shown in FIG. Thereafter, the etching resistance pattern 15 and the pattern 19 of the photoresist film were removed by performing oxygen etching and cleaning with dilute hydrofluoric acid. As shown in FIG. 12, grooves 21 having a pitch of 16 nm × 150 nm were confirmed on the surface of the silicon substrate 11. This silicon substrate can be used as an imprint mold.

(Example 3)
A pattern was formed on the substrate 11 by the same method as in Example 2 except that the coating solution A was changed to the coating solution B. As a result, grooves 21 having a pitch of 16 nm × 150 nm were confirmed on the surface of the substrate. This silicon substrate can be used as an imprint mold.

Example 4
A pattern was formed on the substrate 11 by the same method as in Example 2 except that the coating solution A was changed to the coating solution C. As a result, grooves 21 having a pitch of 38 nm × 150 nm were confirmed on the surface of the substrate. This silicon substrate can be used as an imprint mold.

(Example 5)
A pattern was formed on the substrate 11 by the same method as in Example 2 except that the coating solution A was changed to the coating solution D. As a result, grooves 21 having a pitch of 20 nm × 150 nm were confirmed on the surface of the substrate. This silicon substrate can be used as an imprint mold.

(Example 6)
Here, an example in which the composition 14 shown in FIG. 4 or FIG. 7 has etching resistance will be described.

  First, a guide 20 (width: 300 nm, height: 10 nm) was formed by drawing an electron beam of polystyrene on a 3-inch substrate to prepare a substrate 11 as shown in FIG.

The coating solution D was applied to the guide substrate 11 and annealed at 180 degrees for 5 hours to obtain a pattern in which the polydimethylsiloxane cylinder was oriented parallel to the guide. The thin layer of polydimethylsiloxane produced on the surface layer at this time was peeled off with CF ₄ plasma, and then subjected to oxygen plasma treatment to produce an etching resistant cylinder pattern in which polydimethylsiloxane was oxidized.

  Next, an 80 nm film of ZEP520 (manufactured by Nippon Zeon Co., Ltd.) was formed as a photoresist film 16 on the etching resistant pattern 15 obtained in the same manner as in Example 2 as shown in FIG. A pattern was drawn with an EB exposure apparatus and developed with IPA to form a pattern 19 of a photoresist film having a 50 nm line and a 100 nm space. As a result, as shown in FIG. 10, a lattice-like pattern composed of the etching-resistant pattern 15 and the photoresist film pattern 19 was obtained.

When the silicon substrate was etched with SF ₆ gas using this lattice pattern as a mask, grooves 21 were formed in the substrate 11 as shown in FIG. Thereafter, the etching resistance pattern 15 and the pattern 19 of the photoresist film were removed by performing oxygen etching and cleaning with dilute hydrofluoric acid. As shown in FIG. 12, grooves 21 having a pitch of 45 nm × 150 nm were confirmed on the surface of the silicon substrate 11. This silicon substrate can be used as an imprint mold.

(Example 7)
The magnetic film was processed using the imprint mold obtained in Example 2 to produce a magnetic recording medium.

  First, as shown in FIG. 21, a 20 nm magnetic film 32 is formed on a glass substrate 31, and a novolak resist is spin-coated on the magnetic film 32 to form a 30 nm thick resist film 33. did.

  The imprint mold 30 having the lattice pattern produced in Example 2 was placed on the resist film 33, and a pressure of 2000 bar was applied by a press device, and imprinting was performed as shown in FIG. The imprint mold 30 is immersed in a 2% ethanol solution of a coupling treatment agent (TSL8233 (manufactured by GE Toshiba Silicone) for 30 minutes and dried in an oven at 120 ° C. for 1 hour, whereby the surface is subjected to a mold release treatment beforehand. Oita.

  A grid-like groove was formed in the imprint resist film 33, and a resist pattern 34 as shown in FIG. 23 was obtained. The portion of the resist film remaining at the bottom of the groove is removed by oxygen plasma to expose the magnetic film 32 as shown in FIG. 24, and then the magnetic film 32 is etched by Ar ion milling using the resist pattern 34 as a mask. As shown in FIG. 25, a magnetic film pattern 35 was obtained.

  Finally, the resist pattern 34 was peeled off to manufacture a magnetic recording medium on which a magnetic cell composed of the magnetic film pattern 35 as shown in FIG. 26 was formed. The dimensions of the magnetic cell were 16 nm pitch × 150 nm, and it was confirmed that the imprint mold pattern was transferred.

1 is a plan view of a magnetic recording medium according to an embodiment of the present invention. The phase diagram which shows the composition range which a diblock copolymer phase-separates into a cylinder or a lamella. The perspective view showing 1 process of the manufacturing method of the implant mold which concerns on one Embodiment of this invention. FIG. 4 is a perspective view illustrating a process following FIG. 3. The perspective view showing 1 process of the manufacturing method of the implant mold which concerns on other embodiment. FIG. 6 is a perspective view illustrating a process following FIG. 5. FIG. 7 is a perspective view illustrating a process following FIG. 6. The perspective view showing the process following FIG. FIG. 9 is a perspective view illustrating a process following FIG. 8. FIG. 10 is a perspective view illustrating a process following FIG. 9. FIG. 11 is a perspective view illustrating a process following FIG. 10. FIG. 12 is a perspective view illustrating a process following FIG. 11. The perspective view showing 1 process of the manufacturing method of the implant mold which concerns on other embodiment of this invention. FIG. 14 is a perspective view illustrating a process following FIG. 13. FIG. 15 is a perspective view illustrating a process following FIG. 14. FIG. 16 is a perspective view illustrating a process following FIG. 15. The perspective view showing 1 process of the manufacturing method of the implant mold which concerns on other embodiment of this invention. FIG. 18 is a perspective view illustrating a process following FIG. 17. The perspective view showing 1 process of the manufacturing method of the implant mold which concerns on other embodiment of this invention. FIG. 20 is a perspective view illustrating a process following FIG. 19. The perspective view showing 1 process of the manufacturing method of the magnetic-recording medium based on one Embodiment of this invention. FIG. 22 is a perspective view illustrating a process following FIG. 21. FIG. 23 is a perspective view illustrating a process following FIG. 22. FIG. 26 is a perspective view illustrating a process following FIG. FIG. 25 is a perspective view illustrating a process following FIG. 24. FIG. 26 is a perspective view illustrating a process following FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Magnetic recording medium, 2 ... Track, 3 ... Magnetic material cell, 11 ... Substrate, 12 ... Diblock copolymer film, 13 ... Phase-separated diblock copolymer film, 14 ... Easily etching area | region containing the component of 1st phase , 15 ... Etching-resistant pattern containing second phase component, 16 ... Photoresist film, 19 ... Pattern, 20 ... Guide, 21 ... Groove, 30 ... Imprint mold, 31 ... Media substrate, 32 ... Magnetic film, 33 ... resist film, 34 ... resist pattern, 35 ... magnetic film pattern.

Claims (9)

Forming on the substrate a composition film comprising a composition containing a diblock copolymer and phase-separating into a first phase and a second phase having higher etching resistance than the first phase;
Phase-separating the composition film containing the diblock copolymer into a cylinder or a lamellar shape in a first direction to form an easy-etch region including a component of the first phase extending in the first direction;
Forming a resist film on the composition film containing the phase-separated diblock copolymer;
Forming a pattern extending in a second direction intersecting the first direction on the resist film by electron beam drawing or light exposure; and
And a step of etching the substrate using a resist film patterned by electron beam or light exposure and an etching resistant pattern containing the second phase component as a mask. Forming on the substrate a composition film comprising a composition containing a diblock copolymer and phase-separating into a first phase and a second phase having higher etching resistance than the first phase;
Phase-separating the composition film containing the diblock copolymer into a cylinder or a lamellar shape in a first direction to form an easy-etch region including a component of the first phase extending in the first direction;
Removing an easy-etching region containing the first phase component from the composition film to form an etching-resistant pattern containing the second phase component extending in the first direction;
Forming a resist film on the etching resistant pattern;
Forming a pattern extending in a second direction intersecting the first direction on the resist film by electron beam drawing or light exposure; and
And a step of etching the substrate using a resist film patterned by electron beam or light exposure and an etching resistant pattern containing the second phase component as a mask.   Before forming the composition film containing the diblock copolymer on the substrate, further comprising forming a guide on the substrate, phase-separating the composition film containing the diblock copolymer, 3. The pattern forming method according to claim 1, wherein an easy-etching region including a cylindrical or lamellar first phase component extending in a first direction along the guide is formed.   The diblock copolymer is selected from the group consisting of polystyrene, polymethyl methacrylate, poly (ethylene-alt-propylene), polybutadiene, polyisoprene, polyvinyl methyl ether, polyethylene oxide, polypropylene oxide, polybutylene oxide, and polydimethylsiloxane. The pattern forming method according to claim 1, further comprising: two blocks.   5. The pattern forming method according to claim 1, wherein a silicon compound is further contained in the second phase from which the composition film containing the diblock copolymer is phase-separated. .   6. The pattern according to claim 5, wherein the silicon compound is selected from the group consisting of silicates, hydrogen siloxane, methyl siloxane, methyl siloxane, hydrogen silsesquioxane, and methyl silsesquioxane. Forming method.   The pattern forming method according to claim 1, further comprising a step of removing the etching resistant pattern from the substrate.   An imprint mold comprising a substrate having a lattice pattern processed by the pattern forming method according to claim 1. Forming a magnetic film on a medium substrate;
Forming a resist film on the magnetic film;
An imprint mold having the grid pattern according to claim 8 is imprinted on the resist film, and a grid pattern concave portion is formed in the resist film to obtain a resist pattern composed of convex portions. Process,
And a step of etching the magnetic film using the resist pattern as a mask to form a magnetic film pattern separated by lattice-like grooves.

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