JP2007216501A - Method for producing pattern forming mold and pattern forming mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a pattern forming mold which is good in adhesion between a substrate and a projection having a desired pattern and excellent in durability and can form the pattern exactly, and the pattern forming mold. <P>SOLUTION: The method for producing the pattern forming mold includes a process for forming the projection having the desired pattern on the surface of the substrate from a resist composition containing fine inorganic particles, a hydroxystyrene resin, and a photo-acid generating agent, a process for forming a hard coat layer on the surface of the substrate with the projection formed by the application of a coating solution containing a polysilazane, and a process for baking the substrate with the hard coat layer formed. The amount of the incorporated hydroxystyrene resin is 5-25 pts.wt. per 100 pts.wt. of the fine inorganic particles. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a pattern forming mold and a pattern forming mold. More specifically, the present invention relates to a pattern forming mold manufacturing method and a pattern forming mold that are useful for pattern formation by a photoimprint method.

  In recent years, a pattern transfer technique called an optical imprint method has been proposed. Hereinafter, a pattern forming method by the optical imprint method will be described. A photocurable composition is applied on a substrate, and a mold made of a material having a concavo-convex shape on the surface and having a light-transmitting property such as quartz is pressed. In this state, light is irradiated from the back surface of the mold to cure the photocurable composition to obtain a pattern.

  As the method for producing the mold, an “etching method” and a “sintering method” have been proposed. The “etching method” is a method in which after a resist resin pattern serving as a protective film is formed on a quartz glass substrate, a portion where the protective film is not formed is removed by etching. On the other hand, the “sintering method” is a method in which a convex portion having a desired shape is formed on a substrate with a ceramic precursor, and the substrate and the convex portion are integrated by sintering (for example, see Patent Document 1). ). Therefore, the “sintering method” is more useful than the “etching method” in that the etching process can be omitted.

However, the “sintering method” has a problem in that the adhesion between the substrate and the convex portion is poor and the durability is poor because the substrate and the convex portion are integrated by sintering. In addition, the mold obtained by the “sintering method” has a problem that a pattern cannot be formed accurately because the convex portions formed on the substrate absorb ultraviolet rays.
Japanese Patent Laid-Open No. 11-40548

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to provide good adhesion between the substrate and the convex portion having a desired pattern, excellent durability, and accurate pattern formation. An object of the present invention is to provide a method for manufacturing a pattern forming mold and a pattern forming mold.

  The method for producing a mold for forming a pattern according to the present invention includes a step of forming a convex portion having a desired pattern on a substrate surface with a resist composition containing inorganic fine particles, a hydroxystyrene-based resin, and a photoacid generator; Including a step of applying a coating liquid containing polysilazane to the surface of the substrate on which the hard coat layer is formed, and a step of firing the substrate on which the hard coat layer is formed. , And 5 to 25 parts by weight with respect to 100 parts by weight of the inorganic fine particles.

  In preferable embodiment, the board | substrate in which the said hard-coat layer was formed is baked at 80-300 degreeC.

  In another aspect of the present invention, a pattern forming mold is provided. This pattern forming mold is obtained by the method for manufacturing a pattern forming mold.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the mold for pattern formation and the mold for pattern formation which are excellent in the adhesiveness of the board | substrate and the convex part which has a desired pattern, are excellent in durability, and can form a pattern correctly can be obtained.

  Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.

  The method for producing a mold for forming a pattern according to the present invention includes a step of forming a convex portion having a desired pattern on a substrate surface with a resist composition containing inorganic fine particles, a hydroxystyrene-based resin, and a photoacid generator; A step of applying a coating liquid containing polysilazane to the surface of the substrate on which the hard coat layer is formed, and a step of firing the substrate on which the hard coat layer is formed. Hereinafter, each step will be described with reference to FIG.

A convex part formation process The manufacturing method of the mold for pattern formation of this invention forms the convex part which has a desired pattern with the resist composition containing an inorganic fine particle, a hydroxystyrene resin, and a photo-acid generator on the substrate surface. Process. Any appropriate substrate can be adopted as the substrate used in this step. Preferably, the substrate is made of quartz.

  The resist composition includes inorganic fine particles. Any appropriate material can be adopted as the inorganic fine particles. Specific examples include silica, aluminum oxide, titanium oxide, tin oxide and the like. Silica is preferred. This is because a pattern-forming mold capable of efficiently transmitting ultraviolet rays and forming a pattern more accurately can be obtained.

  Preferably, the inorganic fine particles have a functional group on the surface thereof. Examples of this functional group include a hydroxyl group, an acryl group, a methacryl group, an amino group, and an epoxy group. Preferably, it is a hydroxyl group. This is because it reacts with polysilazane described later to form a strong hard coat layer. As a result, a pattern forming mold having excellent durability can be obtained.

  The shape of the inorganic fine particles is not particularly limited, and may be spherical, elliptical, flat, rod-like, or fibrous. The average particle diameter of the inorganic fine particles is preferably 1 to 1000 nm, more preferably 5 to 100 nm, and particularly preferably 10 to 20 nm. This is because when the average particle diameter of the inorganic fine particles is within the above range, a pattern forming mold capable of efficiently transmitting ultraviolet rays and forming a pattern more accurately can be obtained.

  The inorganic fine particles are preferably dispersed in a solvent. Examples of the dispersed inorganic fine particles include colloidal silica. Colloidal silica is commercially available as an organosilica sol. Specific examples include “Snowtex colloidal silica” (manufactured by Nissan Chemical Industries, Ltd.) and the like.

  The resist composition includes a hydroxystyrene resin. By including a hydroxystyrene-based resin, a mold for pattern formation having excellent reactivity with polysilazane described later and excellent durability can be obtained. The hydroxystyrene-based resin preferably has a phenolic hydroxyl group and / or a carboxyl group. Specific examples of the hydroxystyrene resin include hydroxystyrene resins obtained by (co) polymerizing parahydroxystyrene.

  When the hydroxystyrene-based resin has a phenolic hydroxyl group, a part of the phenolic hydroxyl group is preferably substituted with a protecting group. Specific examples of the substituent include an acetal group, a t-butoxycarbonyl group, a tetrahydropyranyl group, and a trimethylsilyl group.

  The hydroxystyrene resin may be a copolymer with another monomer. Examples of other monomers include t-butyl acrylate, t-butyl methacrylate, and styrene.

  The hydroxystyrene-based resin preferably has a weight average molecular weight of 1000 to 100,000, more preferably 2000 to 50000, and particularly preferably 5000 to 30000.

  The amount of the hydroxystyrene-based resin is 5 to 25 parts by weight, preferably 10 to 25 parts by weight, and more preferably 10 to 15 parts by weight with respect to 100 parts by weight of the inorganic fine particles. By setting it as the said range, the mold for pattern formation which can form a pattern accurately can be obtained that the adhesiveness of a board | substrate and a convex part is excellent, is excellent in durability, and is excellent.

  The resist composition includes a photoacid generator. A commercial item can be used as a photo-acid generator. Specific examples of commercially available products include “TPS-105 (triphenylsulfonium triflate)”, “BBI-106 (iodonium camphor sulfate),“ DAM-301 (diazomethanesulfonium) ”manufactured by Midori Chemical Co., Ltd. Is mentioned.

  The compounding amount of the photoacid generator is 1 to 20 parts by weight, preferably 1 to 10 parts by weight, and more preferably 2 to 5 parts by weight with respect to 100 parts by weight of the hydroxystyrene resin.

  Preferably, the resist composition includes a solvent. The solvent is not particularly limited as long as it can dissolve or disperse the hydroxystyrene resin. Specific examples of the solvent include propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), ethyl lactate (EL), methyl amyl ketone (MAK) and the like.

  The resist composition may contain other components. Examples of other components include surfactants and adhesion assistants.

  Any appropriate method can be adopted as a method of forming the convex portion 20b having a desired pattern on the substrate surface. For example, a step I (FIG. 1A) in which a resist composition is applied to the substrate 10 to form a resist composition layer 20; and a mask M having a hollow portion (bright portion) having substantially the same shape as a desired pattern. Step II (FIG. 1 (b)) of irradiating the resist composition layer 20 with ultraviolet rays through the step; After the ultraviolet irradiation step, the resist composition layer is immersed in an alkaline solution to remove the exposed portion 20a. And a method including Step III (FIG. 1C) (positive type).

  In Step I, any appropriate method can be adopted as a method for applying the resist composition onto the substrate. Specific examples include spin coating and dip coating. The thickness of the resist composition layer can be appropriately set according to the purpose. Typically, it is 0.1 to 5 μm.

  The material of the mask used in step II is not particularly limited as long as it is a material that can block ultraviolet rays. Specific examples include glass and quartz.

In Step II, the wavelength of the light source used for ultraviolet irradiation can be set as appropriate according to the purpose. Typically, it is 210-400 nm, More preferably, it is 210-320 nm. The amount of ultraviolet irradiation is preferably 0.1 to 10 J / cm ² , more preferably 0.5 to 4 J / cm ² .

  Specific examples of the ultraviolet irradiation means U include an ultrahigh pressure mercury lamp, a flash UV lamp, a high pressure mercury lamp, a low pressure mercury lamp, a deep UV lamp, a xenon lamp, a xenon flash lamp, a metal halide lamp, and a light emitting diode (LED). It is done.

  Arbitrary appropriate solutions are employ | adopted as an alkaline solution in the said process III. Specific examples include tetramethylammonium hydroxide aqueous solution. The concentration of the alkaline solution is preferably 1 to 5% by weight. In addition, as an alkaline solution, 2.38 weight% tetramethylammonium hydroxide aqueous solution is generally used. The time for immersing the resist composition layer in the alkaline solution can be appropriately set according to the thickness of the resist composition layer. Typically, it is 5 to 60 seconds.

  In addition, as another method of forming the convex portion 20b having a desired pattern on the substrate surface, a step I of applying a resist composition on the substrate 10 to form the resist composition layer 20 (FIG. 1A). Step II (FIG. 1 (b)) in which the resist composition layer 20 is irradiated with ultraviolet rays through a mask M having a portion other than the hollowed out portion (bright portion) having substantially the same shape as the desired pattern; After the irradiation step, a method including a step III (FIG. 1 (c ′)) of removing an unexposed portion is included (negative type).

B. Hard Coat Layer Forming Step As shown in FIG. 1 (d), the method for producing a pattern forming mold of the present invention forms a hard coat layer 30 by applying a coating liquid on the surface of the substrate 10 on which the convex portions 20b are formed. The process of carrying out is included.

The coating solution contains polysilazane. Polysilazane is a compound (including a polymer) having a structural unit represented by the following formula (1) in the molecule.
Here, R is a hydrogen atom or an organic group. A plurality of R present in the molecule may be the same or different from each other. Specific examples of preferable polysilazane include perhydropolysilazane (polysilazane in which all Rs are hydrogen atoms). When R is a hydrogen atom, it can be converted to a purer silica in the firing step described below. As a result, it is possible to obtain a pattern forming mold that is excellent in transparency and capable of forming a pattern accurately.

  The polysilazane may have a chain, a ring, and / or a crosslinked structure. The number average molecular weight of the polysilazane is preferably 300 to 15000, more preferably 300 to 10,000, and particularly preferably 500 to 2,000.

  In the present invention, two or more polysilazanes having a specific structure may be used in combination. Furthermore, a copolymer of polysilazane and another organic or inorganic polymer (preferably an inorganic polymer) may be used depending on the purpose.

  Preferably, the coating solution contains a solvent. This solvent is not particularly limited as long as it can dilute polysilazane and does not react with polysilazane. Specific examples of the solvent include toluene, xylene, dibutyl ether, PGMEA, ethyl lactate, and cyclohexanone.

  The polysilazane concentration in the coating solution is appropriately set according to the number average molecular weight of the polysilazane and the thickness of the polysilazane coating film described later. Typically, the polysilazane concentration in the polysilazane coating solution is 1 to 5% by weight.

  Examples of the coating method of the coating solution include a dip coating method, a spin coating method, and a spray coating method.

  The thickness of the hard coat layer is preferably 1 to 500 nm, more preferably 1 to 50 nm, and particularly preferably 1 to 5 nm. When the thickness of the hard coat layer is within the above range, a pattern forming mold having excellent durability can be obtained.

C. Firing Step The method for producing a pattern forming mold of the present invention includes a step of firing the substrate 10 on which the hard coat layer 30 is formed. After firing, as shown in FIG. 1 (d), the substrate 10 and the convex portion 20b can be integrated, and the pattern forming mold 100 can be obtained. The firing temperature is preferably 80 to 300 ° C, more preferably 80 to 160 ° C, and particularly preferably 80 to 120 ° C.

  The firing step is preferably performed in an air atmosphere and / or a water vapor atmosphere. This is because the reaction between the inorganic fine particles in the resist composition and the polysilazane is promoted. As a result, a mold having excellent durability can be obtained. The firing time is preferably 30 minutes to 3 hours, more preferably 30 minutes to 1 hour.

D. Others The method for producing a pattern forming mold of the present invention preferably includes a step of forming an antifouling layer on the substrate surface after the baking step. By forming the antifouling layer, a mold excellent in releasability from the photocurable composition after photocuring can be obtained during pattern formation. Any appropriate material can be adopted as the antifouling agent for forming the antifouling layer. A specific example is a fluororesin.

  The operation of the present invention will be described below. ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness of a board | substrate and a convex part is excellent, it is excellent in durability, and the manufacturing method of the mold for pattern formation which can form a pattern correctly, and the mold for pattern formation can be obtained. Further, by forming a convex portion with a resist composition containing a predetermined amount of inorganic fine particles, a hydroxystyrene resin and a photoacid generator, and forming a hard coat layer with a coating liquid containing polysilazane, a relatively low temperature is obtained. It is one of the excellent features of the present invention that a mold for forming a pattern that is excellent in durability and capable of forming a pattern accurately under firing conditions is obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.

[Example 1]
(Preparation of resist resin composition)
40% of the phenolic hydroxyl group of polyhydroxystyrene (trade name: VP8000, manufactured by Nippon Soda Co., Ltd.) was substituted with an ethoxyethyl group according to a conventional method. 10 parts by weight of this resin, 0.3 parts by weight of triphenylsulfonium triflate (trade name: TPS-105, manufactured by Midori Chemical Co., Ltd.) as a photoacid generator, and 75 parts by weight of propylene glycol monomethyl ether acetate (PGMEA) as a solvent And a part were mixed to prepare a resist resin composition.

(Preparation of resist composition)
216 parts by weight of organosilica sol (trade name: PMA-ST, solid content: 30% by weight, manufactured by Nissan Chemical Industries, Ltd.) and 60 parts by weight of the resist resin composition obtained above are stirred at room temperature for 1 hour. Thus, a resist composition was prepared. Here, the weight ratio of the organic solid portion to the inorganic solid content was 11: 100.

(Formation of convex parts)
As shown in FIG. 1A, a resist composition layer A having a thickness of 0.5 μm was formed by applying the resist composition obtained above onto a quartz substrate having a thickness of 1 mm by a spin coating method. Next, the surface of the resist composition layer A was irradiated with ultraviolet rays with a large mask alignment apparatus M-2L (manufactured by Mikasa Co., Ltd.) through a mask (a stripe shape having a bright portion of 0.6 μm and a dark portion of 0.6 μm). At that time, the irradiation wavelength was 248 nm and the irradiation light amount was 4 J / cm ² . Thereafter, after the ultraviolet irradiation step, the substrate on which the resist composition layer A was formed was immersed in an alkaline solution (tetramethylammonium hydroxide aqueous solution, concentration: 2.38 wt%) for 10 seconds to obtain a laminate A.

(Formation of hard coat layer)
Polysilazane (component name: polyhydroxypolysilazane, solvent: xylene, concentration: 20% by weight, trade name: Aquamica NN110, manufactured by AZ Electronic Materials Co., Ltd.) was diluted to 5% by weight with toluene to prepare a coating solution. The obtained coating solution was applied to the surface of the laminate A (side on which the convex portions were formed) by a spin coating method and dried in an oven (100 ° C.) for 1 hour to form a hard coat layer.

(Baking)
The laminate A on which the hard coat layer was formed was baked at 100 ° C. for 1 hour in an air atmosphere to obtain a pattern forming mold.

(Formation of antifouling layer)
The pattern forming mold obtained above was immersed in a demnum solvent (trade name, manufactured by Daikin Industries, Ltd.) containing 1% by weight of OPTOOL (trade name, manufactured by Daikin Industries, Ltd.) for 1 minute. Thereafter, the mold for pattern formation was taken out of the solution, left for 1 minute, and washed with demnum solvent. Then, it was made to react at 80 degreeC for 1 hour in water vapor | steam atmosphere. After the reaction, the reaction mixture was cooled to room temperature, rinsed with distilled water, and dried in an oven (120 ° C.) for 30 minutes to form an antifouling layer.

[Comparative Example 1]
The same operation as in Example 1 was conducted except that a resist composition was prepared with 228 parts by weight of organosilica sol (trade name: PMA-ST) and 23 parts by weight of the resist resin composition.

  The mold for pattern formation obtained in Example 1 was observed with a scanning probe microscope (SPA-400, manufactured by SII Nano Technology Co., Ltd.). The observation results are shown in FIG. On the other hand, in Comparative Example 1, the resist composition was dissolved in an alkaline solution when the convex portions were formed, and a pattern forming mold could not be created.

Using the pattern forming mold obtained in Example 1, a pattern was formed in the following manner.
(Preparation of inorganic fine particles having a photopolymerizable group)
1500 parts by weight of organosilica sol (trade name: IPA-ST, manufactured by Nissan Chemical Industries, Ltd.), 135 parts by weight of methacryloxypropyltrimethoxysilane (trade name: Silaace S710, manufactured by Chisso Petrochemical Co., Ltd.), 0.05 N Inorganic fine particles having a photopolymerizable group (solid content: 450 parts by weight) were prepared by stirring 40 parts by weight of hydrochloric acid at room temperature for 24 hours.

(Preparation of photocurable composition)
To the inorganic fine particles having a photopolymerizable group obtained above, 450 parts by weight of trimethylolpropane EO-added triacrylate (trade name: Biscote V360, manufactured by Osaka Organic Chemical Industry) was added and mixed. Thereafter, the solvent in the organosilica sol was distilled off under reduced pressure using an evaporator (manufactured by Tokyo Science Equipment Co., Ltd.) to obtain an inorganic fine particle-containing monomer. 100 parts by weight of the inorganic fine particle-containing monomer, 30 parts by weight of 2,2,2-trifluoroethyl acrylate (trade name: Biscoat 3F, manufactured by Osaka Organic Chemical Industry), and tetraethylene glycol dimethacrylate (trade name: light ester 4EG) And 20 parts by weight of Kyoeisha Chemical Co., Ltd.). As a photopolymerizable initiator, bis (2,5-dimethoxybenzoyl) -2,4,4-trimethyl-benzylphosphine oxide and 1-hydroxy-cyclohexyl-phenyl-ketone were used at a ratio of 1: 3. 1.5 parts by weight of mixed Irgacure 1800 (trade name; manufactured by Nagase Sangyo Co., Ltd.) was mixed to obtain a photocurable composition.

(Pattern formation)
The photocurable composition obtained above was dropped onto the substrate and sandwiched between the pattern forming molds obtained in Example 1. Next, the substrate and the pattern forming mold were clipped and irradiated with ultraviolet light with a high-pressure mercury lamp while embossing. The amount dropped was about 0.1 mL / cm ² . The irradiation light quantity of ultraviolet light was 1 J / cm ² in terms of 365 nm wavelength.

  The pattern obtained above was observed with a scanning probe microscope (SPA-400, manufactured by SII Nano Technology Co., Ltd.). The observation results are shown in FIG. As shown in FIG. 3, the pattern could be formed accurately.

  The method for producing a mold for pattern formation and the mold of the present invention can be used for pattern formation in various fields such as semiconductors, micro optical parts, MEMS and the like.

It is the schematic which shows the manufacturing method of the mold for pattern formation by preferable embodiment of this invention. 3 is an observation photograph of the pattern forming mold obtained in Example 1. FIG. 2 is an observation photograph of a pattern obtained using the pattern forming mold obtained in Example 1. FIG.

Claims (3)

Forming a convex portion having a desired pattern on a substrate surface with a resist composition containing inorganic fine particles, a hydroxystyrene-based resin, and a photoacid generator;
A step of applying a coating liquid containing polysilazane to form a hard coat layer on the substrate surface on which the convex portions are formed;
Baking the substrate on which the hard coat layer is formed,
The amount of the hydroxystyrene-based resin is 5 to 25 parts by weight with respect to 100 parts by weight of the inorganic fine particles.   The manufacturing method of the mold for pattern formation of Claim 1 which bakes the board | substrate in which the said hard-coat layer was formed at 80-300 degreeC. A pattern forming mold obtained by the method for producing a pattern forming mold according to claim 1.