JP2001100419A - Micropattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a pattern of nanometer to micron order having appreciable regularity by utilizing the phase separation of a blended polymer. SOLUTION: The micropattern is formed through a step for forming a thin film of a micropattern forming material comprising a polymer blend containing two or more polymers on a base, a step for forming a phase separated structure fixed in the formation and growth of nuclei in the thin film, a step for breaking the principal chain of at least one of the polymers by irradiating the thin film with high energy beams, a step for selectively removing the phase of the polymer with the broken principal chain and a step for patterning the base through the phase of the remaining polymer as a mask.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material capable of forming a pattern on the order of nanometers to microns on a base material in a self-organizing manner and using the mask as a mask to form a highly regular micropattern on the base material. In addition, the present invention forms a structure of nanometer to micron order in a bulk in a self-organizing manner, and uses it as a highly ordered microstructure as it is, or uses this as a template to form another highly structured microstructure. A material that can form The materials of the present invention include hard disks, solar cells, photoelectric conversion elements, light emitting elements, displays, light modulation elements, and organic FETs.
Applied to the manufacture of elements, capacitors, etc.

[0002]

2. Description of the Related Art The need for fine patterns and structures is increasing with the advance of the performance of electronic components. For example, an LSI or a liquid crystal display requires a fine processing technology. Many devices, such as batteries and capacitors, require a large surface area with a small volume. In the future, high-density three-dimensional mounting technology will be required. Various techniques are used for such processing, but the more fine processing is required, the higher the manufacturing cost.

For example, LSIs, hard disk drives,
Microfabrication using photolithography used in a process of manufacturing electronic components such as a display is performed as follows. First, a resist solution is applied on a substrate or the like to form a resist film, and the obtained resist film is subjected to pattern exposure, and then subjected to processing such as alkali development to form a resist pattern. Next, using this resist pattern as an etching-resistant mask, the exposed surface of the substrate or the like is dry-etched to form fine-width lines or openings, and finally, the resist is removed by ashing.

[0004] Such a fine processing method is effective for forming a fine pattern of 1 µm or more, and is widely adopted. Recently, using an electron beam or excimer laser as an exposure light source, or using super-resolution technology,
It has become possible to resolve a pattern of about m. However, in order to form a nano-scale pattern near the optical resolution limit by lithography, it is necessary to use a very expensive exposure apparatus. Further, since the resist has low stability to an atmosphere, it is necessary to take measures such as mounting a chemical filter in order to control the atmosphere in the clean room. Therefore, a huge investment is required for the method of forming a fine pattern by lithography.

[0005] On the other hand, patterning on the order of nanometers to microns is required, but there are fields where precision is not required, such as lithography. However, since a simple method has not been known, a fine pattern has to be formed even in such a field by a method such as lithography using an electron beam or deep ultraviolet rays. As described above, in such a technique, as the processing size becomes smaller, the operation becomes more complicated, and the problem of enormous investment is inevitable.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a material and a method which can easily form a nanometer to micron order pattern having considerable regularity by utilizing the phase separation of a blended polymer. It is in.

[0007]

The micropattern-forming material of the present invention is a micropattern-forming material comprising a polymer blend of two or more polymers, wherein the horizontal axis represents the volume fraction of one polymer and the temperature represents the temperature. In the phase diagram with the vertical axis,
It is sandwiched between the binodal curve that is the boundary between the one-phase state and the multi-phase state and the spinodal curve that is the boundary where phase separation occurs through spinodal decomposition, and in the region where phase separation occurs through the nucleation and growth process. It has a corresponding composition. A feature of the present invention is that a combination of two or more polymers capable of removing at least one polymer component is used among the phase separation structures formed from such a polymer blend.

The following are specific examples of the micropattern forming material of the present invention.

(A) A micro-polymer blend comprising at least one polymer having hydrogen at the α-position carbon of the monomer unit and at least one polymer having an alkyl group or halogen at the α-position carbon of the monomer unit. Pattern forming material.

(B) The ratio of N / (Nc-No) of the monomer units constituting the polymer is 1.4 or more (however, N
Is a total number of atoms in the monomer unit, Nc is the number of carbon atoms in the monomer unit, and No is the number of oxygen atoms in the monomer unit). A micropattern forming material comprising a polymer blend containing two or more polymers.

(C) A micropattern-forming material comprising a polymer blend containing two or more polymers having mutually different thermal decomposability at a temperature of 120 ° C. or higher.

(D) A micropattern-forming material comprising a polymer blend containing at least one alkali-soluble polymer and at least one alkali-insoluble polymer. The alkali-soluble polymer also includes a polymer that can be changed from alkali-insoluble to alkali-soluble by some treatment.

In the present invention, as a method of forming a micropattern using the above-described micropattern forming material, the following method can be mentioned.

The first method for forming a micropattern according to the present invention comprises the steps of: providing at least one polymer having hydrogen on the α-position carbon of the monomer unit and at least one polymer having an alkyl group or halogen at the α-position carbon of the monomer unit on the base;
Forming a thin film of a micropattern-forming material comprising a polymer blend containing at least one kind of polymer; forming a phase-separated structure in the thin film; A step of cutting the main chain of the polymer, a step of selectively removing the polymer phase in which the main chain has been cut, and a step of processing the base using the remaining polymer phase as a mask. I do.

[0015] The second method of forming a micropattern according to the present invention is a method of forming a micropattern on a base, wherein the monomer unit constituting the polymer is N-type.
/ (Nc-No) ratio of 1.4 or more (where N is the total number of monomer units, Nc is the number of carbon atoms of the monomer unit, and No is the number of oxygen atoms of the monomer unit) Forming a thin film of a micropattern forming material comprising a polymer blend containing
Forming a phase-separated structure in the thin film, etching the thin film to selectively remove at least one polymer phase, and processing a base using the remaining polymer phase as a mask. It is characterized by having.

The third method of forming a micropattern according to the present invention is to form a thin film of a micropattern forming material comprising a polymer blend containing two or more polymers having different thermal decomposabilities at a temperature of 120 ° C. or more on a base. Forming, forming a phase-separated structure in the thin film, heating the thin film to 120 ° C. or higher to selectively pyrolyze and remove at least one polymer phase, and Processing the base using the polymer phase as a mask.

A fourth method of forming a micropattern according to the present invention is a thin film of a micropattern forming material comprising a polymer blend containing at least one alkali-soluble polymer and at least one alkali-insoluble polymer on a substrate. Forming a phase-separated structure in the thin film, developing the thin film with an alkali developer to selectively remove the alkali-soluble polymer phase, and removing the remaining polymer phase. Processing a base as a mask.

In the method of forming a micro pattern by pattern transfer according to the present invention, a step of forming a pattern transfer film on a base and a step of forming a thin film of any of the above-mentioned micro pattern forming materials on the pattern transfer film Forming a phase-separated structure in the thin film, selectively removing at least one polymer phase from the thin film, and etching the pattern transfer film using the remaining polymer phase as an etching mask. Transferring the pattern of the phase separation structure to the pattern transfer film, and transferring the pattern of the phase separation structure to the base by etching the base using the pattern transfer film to which the pattern of the phase separation structure has been transferred as an etching mask. And a step of performing To.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In general, a phenomenon called polymer phase separation involves 2
There are macro phase separation, which is phase separation between two or more kinds of polymer molecules, and micro phase separation, which is intramolecular phase separation observed in block copolymers and graft copolymers. In the present invention, unless otherwise specified, phase separation refers to macro phase separation, which is phase separation between polymer molecules. In macro phase separation, the scale of fluctuation generation is about 1 μm, so that a phase separation structure larger than the order of μm is formed in principle. However, since two types of polymer chains can be completely separated by macro phase separation, after a long time, two types of polymer chains are completely separated.
Divide into phases. However, not all blend polymers cause phase separation, and the conditions of the blend polymer that can form a phase-separated structure having a relatively high regularity pattern, which is the object of the present invention, are considerably limited.

The blended polymer used in the micropattern forming material of the present invention has a one-phase state when a phase diagram is prepared with the volume fraction of one kind of polymer constituting the blended polymer as abscissa and the temperature as ordinate. Between the binodal curve, which is the boundary line between the phase and the multiphase state, and the spinodal curve, which is the boundary line where phase separation occurs through spinodal decomposition, and corresponds to the region where phase separation occurs through the nucleation and growth process Having. This will be described with reference to FIG.

FIG. 1 shows an example of a UCST (Upper Critical Solution Temperature) type phase diagram of a blend polymer composed of an A polymer and a B polymer. The horizontal axis is the volume fraction of the A polymer, and the vertical axis is the temperature. In FIG. 1, the solid line is called a binodal curve (binodal curve). In the region above this curve, the two polymers are completely mixed to form a one-phase state, and in the region below this curve, two types of polymers are formed. The polymer undergoes phase separation into a two-phase state. The binodal curve can be created, for example, by examining the temperature at which the cloud point occurs when the temperature is lowered from the one-phase state for a blended polymer having a predetermined composition. The dashed line is called the spinodal curve (cusp curve), and in the region below this curve, the two polymers undergo phase separation through spinodal decomposition. On the other hand, in the region sandwiched between the binodal curve and the spinodal curve (the shaded region in FIG. 1), the two polymers undergo phase separation through the nucleation and growth process, and eventually complete two phases. However, considerable regularity is observed during the nucleation and growth process. Note that LCST
In the (lower critical solution temperature) type phase diagram, the upper and lower sides of the phase diagram are inverted with respect to the temperature in FIG. 1, and the above relationship with the temperature is switched.

FIG. 2 shows an example of polystyrene and poly-2-
Blend polymer with chlorostyrene (PS / P2Cl
(S) shows phase-separated structures with various compositions (Polymer Alloy, edited by The Society of Polymer Science, Tokyo Kagaku Dojin, 199)
3). As shown in this figure, it can be seen that various forms can be taken according to the composition ratio of the A polymer and the B polymer. At a composition ratio where the composition of the minority phase is low, such as when the volume ratio [PS] / [P2ClS] is 32/68 or 70/30, the minority phase aggregates to form spherical domains fairly regularly. If the temperature is lowered below the glass transition temperature during this process, the phase separation stops and the structure is fixed. Also, when the viscosity is sufficiently high, the structure may still be fixed.
On the other hand, when the composition ratio of the two phases is from 7: 3 to 1: 1, spinodal decomposition generally occurs to form a three-dimensionally complicated structure, and thus no regularity is observed.

In the present invention, a blended polymer having a composition corresponding to the shaded area in FIG. 1 is used at a predetermined temperature, and a regular pattern in the nucleation and growth process (for example, a dot pattern such as the two examples at both ends in FIG. 2) is used. ), And as will be described in detail later, a micro pattern is formed by various methods.

Next, the thermodynamic conditions relating to the phase separation of the blend polymer will be described. The phase separation of the blend polymer is performed through a process of melting the blend polymer, annealing at a temperature between the glass transition temperature and the phase transition temperature to form a phase separation structure, and then fixing the phase separation structure at room temperature. You. Alternatively, a phase-separated structure can be formed by dissolving the blend polymer in a solvent, spin coating or casting. At this time, unless the process conditions such as temperature and time are strictly defined, it is difficult to obtain a desired phase separation structure having considerable regularity.

Regarding the conditions under which the blend polymer causes phase separation, the above thermodynamics at the time of annealing may be considered.
According to the Flory-Haggins theory, the free energy of mixing ΔG shown below must be positive for the two A and B polymers to phase separate.

[0026]

(Equation 1)

In the formula (1), N is the degree of polymerization of the polymer (molecular weight of polymer / molecular weight per monomer), φ _A
Is the volume fraction of the A polymer, χ is the interaction parameter between the A and B polymers, R is the gas constant, and T is the absolute temperature.

When ΔG on the left side of the equation (1) is negative, the two types of polymer chains are mixed, and when ΔG is positive, phase separation occurs.
The first and second terms on the right side are entropy terms of the polymer chain and are always negative. However, as the molecular weight (degree of polymerization) increases, the negative value decreases and approaches zero, which is advantageous for phase separation. The third term is the enthalpy term, 2
It represents the repulsion of the species polymer chains.

The composition corresponding to the region sandwiched between the binodal curve and the spinodal curve is as follows:
It means that the composition satisfies the conditions of ∂G / ∂φ ≧ 0 and ∂ ² G / ∂φ ² ≦ 0 with respect to the free energy of the equation (1).

If the interaction parameter χ in the equation (1) is large, the repulsive force between the two types of polymer chains is increased, making it difficult for the two types of polymer chains to be mutually compatible, and to cause phase separation. χ is a temperature-dependent function and is represented by the following equation.

[0031]

(Equation 2)

Χ can be obtained experimentally,
The experiment involves considerable difficulty. Refer to the Polymer Handbook for parameters of typical polymer combinations.
(John Wiley & Sons 1999). Instead, the interaction parameter χ is approximately represented by the following relational expression using a generally known value called a solubility parameter δ.

[0033]

(Equation 3)

Based on the equations (3) and (1), if the difference between the solubility parameters of the two polymers is known, it is possible to predict whether or not a certain blend polymer will undergo phase separation before mixing. The standard for causing the blended polymer to undergo phase separation is 2
The solubility parameter of the seed polymer is 1 cal ^0.5 / cm
^1.5 or more difference. On the other hand, if the difference between the solubility parameters is too large, it becomes difficult for the two polymers to mix, so that the difference between the solubility parameters of the two polymers is 5 cal ^0.5 / cm ^1.5 or less, and further 3 cal ^0.5 / cm.
It is preferably ^1.5 or less.

As described above, the higher the degree of polymerization of the polymer, the more the phase separation is likely to occur. Conversely, the lower the molecular weight, the less the phase separation occurs. However, if the molecular weight of the polymer is too large, it is difficult for the two types of polymers to be mixed, so that the molecular weight of the polymer is preferably 100,000 or less, more preferably 30,000 or less. This is equal to N in equation (1).
ΔG _{for A} and / or N _B is greater increases, because the repulsive force between the polymer increases. In particular, in order to progress the phase separation through the nucleation and growth process, the molecular weight of the polymer constituting the polymer blend of the present invention must be:
Weight average molecular weight of both A and B polymers is 5000
Approximately 10,000 is optimal.

From the equation (1), the following relational expression holds between χ and the degree of polymerization N.

[0037]

(Equation 4)

From the equation (4), the minimum molecular weight of the blend polymer composed of the A polymer and the B polymer can be determined. Conversely, from this formula, when the molecular weight of the blend polymer is determined, a combination of the A polymer and the B polymer can be selected. From this equation, it can be seen that phase separation is most likely to occur when N _A = N _B , that is, when the composition ratio is 50:50. This indicates that it is sometimes difficult to form a sea-island structure in which the islands with a biased composition are particularly small.

Further, in order to obtain a phase-separated structure having a uniform structure size, a composition ratio may be adjusted by blending a copolymer such as a block copolymer, a graft copolymer or a random copolymer. At this time, if there is too much difference in solubility between the two polymers, phase separation between the copolymer and the homopolymer may occur. In order to minimize this phase separation, it is preferable to reduce the molecular weight of the homopolymer. For example, when the AB copolymer is added to the A homopolymer and the B homopolymer, if the molecular weight of the homopolymer is reduced, the negative value of the entropy term of the Flory-Huggins equation becomes large, and the AB copolymer and both homopolymers are added. This is because they are easily mixed. The molecular weight of the A homopolymer is preferably smaller than the molecular weight of the A block of the AB copolymer. The same applies to the B homopolymer. Given the thermodynamic stability, the molecular weights of the A and B homopolymers are
More preferably, it is smaller than 2/3 of the molecular weight of the block or B block. On the other hand, if the molecular weight of the A homopolymer is less than 1,000, it is not preferable because it may be dissolved in the B block of the AB copolymer. The same applies to the B homopolymer. Further, considering the glass transition point, the molecular weight is more preferably 3000 or more.

It is desirable that the solvent for dissolving the blend polymer is a good solvent for the two kinds of polymers constituting the blend polymer. This is because the repulsive force between the polymer chains is proportional to the square of the difference between the solubility parameters of the two polymer chains as shown in the equation (3), so that the difference between the solubility parameters is reduced to minimize the free energy of the system. In order to When a thin film is formed, 150
It is preferable to use a solvent having a high boiling point of not lower than ° C. because a uniform initial state can be formed. On the other hand, when fabricating a bulk structure, it is preferable to use THF or toluene methylene chloride having a low boiling point. When forming a pattern forming film made of a micro pattern forming material to form a pattern, it is preferable to apply a uniform solution of the micro pattern forming material by a spin coating method, a dip coating method, or the like. This is because it is possible to prevent the history at the time of film formation from remaining by forming a film from a uniform solution. If the coating liquid is not uniform due to the formation of micelles with relatively large particle size in the solution, an inappropriate phase separation structure is mixed in, making it difficult to form a regular pattern or forming a regular pattern It is not preferable because it takes time to perform.

At the interface between two types of polymer chains, tension acts on one phase due to the difference in surface energy. The relationship between the surface energy and the surface tension has the following relationship via the solubility parameter δ.

[0042]

(Equation 5)

[0043]

(Equation 6)

[0044] In the above formula, gamma is the surface tension, V is a free energy of molar volume, Delta] E ^V Excessive surface components. Especially high surface energy of the polymer is due to the increase Delta] E ^V energy is large when the polymer chains in the bulk is emitted into the vacuum. In other words, the higher the energy, the higher the tendency to round inward in an attempt to reduce the surface area, and the higher the surface energy. Thus, when two different polymer chains are in contact, it is believed that the polymer chain with the higher surface energy tends to curl more.

As a result, the phase diagram is shifted toward the polymer phase having a large surface energy, that is, a large value of the solubility parameter. This indicates that the composition forming a domain structure such as a lamella, a cylinder, and a sea-island structure is slightly biased depending on the combination of two types of polymer chains. Specifically, if the solubility parameters of the two polymers that make up the blend polymer are different by 1 cal ^0.5 / cm ^1.5 , the optimal composition will move to the larger of the 5% solubility parameter.

The thickness of the interface between the polymer phases is also an important factor. The interface between the two types of polymer chains is not clearly divided into the A phase and the B phase with an extremely thin surface as a boundary, but has a certain thickness. If this thickness is greater than the size of the domain, the structure will not grow. Assuming that the thickness of the interface between these two types of polymers is L, the heterogeneous Hetzholtz free energy ΔF in which the concentration change follows a Gaussian distribution is given by the following equation.

[0047]

(Equation 7)

Here, Δfm (φ) is a term dependent only on the local concentration φ, k (∇φ) ² is an excess free energy due to the existence of the concentration gradient ∇φ, and k (> 0) is a quadratic expansion. The coefficient when taking the terms up, v ₀ is the lattice volume. The free energy when there is no interface is Δfo, and Δf = Δfm−
If Δfo is given, the surface tension γ is given by the following equation (8).

[0049]

(Equation 8)

Here, assuming that z is perpendicular to the interface, the thickness L of the interface is given by the following equation (9).

[0051]

(Equation 9)

At this time, the polymer having a small surface energy difference upon contact with the substrate segregates on the substrate side. For example,
Polystyrene-polymethyl methacrylate (PS-PM
In the MA) -based blend polymer, PMMA precipitates closer to the substrate. Conversely, in a polystyrene-polybutadiene (PS-PB) -based blend polymer, PS precipitates on the substrate side.

In this case, the optimum composition ratio of the blended polymer cannot be determined unconditionally due to the interaction with the substrate.
I can predict to some extent. That is, when the phase having a small surface energy with the substrate is the minority phase, the amount of the polymer existing on the substrate surface increases, so that the composition of the minority phase needs to be larger. For example, in the PS-PMMA system,
Since PMMA tends to precipitate on the substrate surface, the composition under which PMMA forms islands must be higher than the composition under which PS forms islands under the same conditions. However, at this time, the optimum composition of the sphere rarely has the same tendency due to the difference in the surface tension. The distribution of the size of the structure is different due to the difference in surface tension between the two polymers, and the interaction with the substrate does not make the optimal composition ratio symmetric when each of the two polymers is rich.
For example, when the A polymer has an affinity for the substrate and the A polymer forms a dot on the substrate, the optimal composition is A: B =
20:80. However, when the B polymer forms dots, A: B = 85: 15. This is because when the polymer is adsorbed on the substrate surface in the form of dots, an extra volume is required.

In order to form a phase-separated structure with the blend polymer, the volume fraction of two phases (referred to as A phase and B phase) is important. For example, in order to form a sea-island structure, the volume fraction of one phase is set in the range of 5 to 40%, preferably 10 to 35%, and more preferably 15 to 30%. The lower limit is defined by the required island density and the upper limit is defined by the volume fraction that maintains the sea-island structure. Also, Equation 1
In the case of a thin film having a thickness of about 0 nm, the above-described optimum value is reduced by about 2 to 5% because the influence of the interface is large. Note that if this value is exceeded, the structure will be different from the sea island. To adjust the volume fraction, the mixing ratio of the polymer may be controlled, or the molecular volume of the polymer chain may be controlled. Various techniques can be considered for controlling the molecular volume of the polymer chain. For example, the molecular volume of an alkyl group or a counter anion may be changed when a polyvinyl pyridine chain is quaternized with an alkyl group. Further, a substance having good affinity for a specific phase may be mixed to adjust the volume fraction of the phase.

In order to form a good phase separation structure, A
It is necessary that the polymer chains and the B polymer chains are incompatible with each other. In order to form a good phase separation structure using such mutually incompatible polymer chains, the molecular weight of each block is preferably 3000 or more.

Next, the micropattern forming material of the present invention and a method of forming a micropattern using the same will be described in more detail.

The micropattern-forming material of the present invention is obtained by phase-separating two or more kinds of polymers having different properties from each other so that at least one kind of polymer can be selectively removed by some method through a nucleation and growth process. It consists of a polymer blend mixed to give the composition obtained. Then, after subjecting the polymer blend to phase separation and performing a treatment for changing the state or property of at least one polymer as necessary, at least one polymer is selectively removed to form a desired micro pattern. Can be formed. A specific combination of two or more polymers constituting the micropattern forming material of the present invention and a pattern forming method suitable for the polymer blend will be described by classifying them into the following (A) to (D).

(A) When a polymer blend containing at least one polymer having hydrogen at the α-position carbon of the monomer unit and at least one polymer having an alkyl group or halogen at the α-position carbon of the monomer unit is used. Will be described. These polymers have different resistances to energy rays. In other words, the main chain of the polymer with hydrogen bonded to the α-position is not broken even when irradiated with energy rays, but the main chain is broken with the energy beam when the polymer is bonded with an alkyl group or halogen at the α-position. . The polymer whose main chain has been cut can be selectively removed by wet etching, volatilization by heat treatment, or dry etching.

Accordingly, a thin film of the above polymer blend is formed on a base, a phase-separated structure immobilized during the nucleation and growth process is formed in the thin film, and the thin film is irradiated with high-energy rays to form at least one polymer. After the main chain is cut, the polymer phase in which the main chain has been cut is selectively removed, and the micropattern can be transferred by processing the base using the remaining polymer phase as a mask.

As energy rays, β rays (electron rays),
X-rays, γ-rays, heavy particle beams, and the like. Among these, β-rays, X-rays and γ-rays are excellent because they have excellent transparency into the polymer thin film and can be processed at low cost. Particularly, β-rays and X-rays are preferable, and β-rays having high decomposition efficiency by irradiation are most preferable. As a β-ray (electron beam) source, for example, various electron beam accelerators such as Cockloft-Walton type, Van degraft type, resonance transformer type, insulating core transformer type, or linear type, dynamitron type, high frequency type Can be.

Examples of the polymer whose main chain is decomposed by energy rays include the α-position of a monomer unit such as polypropylene, polyisobutylene, poly α-methylstyrene, polymethacrylic acid, polymethyl methacrylate, polymethacrylamide, and polymethyl isopropenyl ketone. And a polymer having an alkyl group. Similarly, a polymer in which the α-position of a monomer unit is substituted with a halogen has higher main chain decomposability. In addition, fluorinated (halogenated) alkyl groups such as polytrifluoromethyl methacrylate, polytrifluoromethyl-α-acrylate, polytrifluoroethyl methacrylate, polytrifluoroethyl-α-acrylate, and polytrichloroethyl-α-acrylate The substituted (meth) acrylate is
This is more desirable because of its high sensitivity to energy rays. When the energy ray is an X-ray, it is desirable that the metal element is contained in the polymer chain because the decomposition efficiency is improved.

On the other hand, the resistance to energy rays is high,
Polymers whose main chain does not decompose even when irradiated with energy rays include those having hydrogen at the α-position of monomer units such as polyethylene, polypropylene, polystyrene, polyacrylic acid, polymethyl acrylate, polyacrylamide, and polymethyl vinyl ketone. Can be In addition,
It is more preferable that these polymers crosslink by irradiation with energy rays.

The polymer whose main chain has been cut by the irradiation of energy rays can be removed by wet etching by washing with a solvent or volatilization by heat treatment. Patterns and structures can be formed. This is a great advantage because some electronic materials cannot be used for a dry etching process, or even if they can be used, wet etching is preferable in terms of cost.

For example, when a thin film of a blend polymer of PS and PMMA is irradiated with β-rays (electron beams), the main chain of PMMA is cut, and only the PMMA phase is dissolved in the developer. As a developing solution, methyl isobutyl ketone (MIB
K) is used. To adjust the solubility, isopropyl alcohol (IPA) or a surfactant may be added. Further, since the decomposed polymer has a low molecular weight, it can be easily volatilized and removed by heat treatment or the like.

Among the above-mentioned energy rays, in particular, β rays can be effectively used not only for a thin film but also for a bulk molded product. That is, since β-rays have good permeability to organic substances, for example, when one of two phases is decomposed by a β-ray such as a methacrylic polymer, the main chain is decomposed.
The polymer inside the bulk also decomposes. Therefore, when a three-dimensional molded body is produced from the blended polymer and then developed by irradiation with β-rays, a porous structure in which regular pores on the order of nanometers are formed while maintaining the three-dimensional structure can be easily obtained. be able to. Such a porous structure has regular pores and a very large specific surface area, so that it can be used for an electrolyte support such as a polymer battery or a capacitor, or a hollow fiber.

For example, Japanese Patent Application Laid-Open No. H11-80414 describes a method for producing a porous body by decomposing a polymer chain by irradiating ultraviolet rays. However, ultraviolet light has poor transparency to organic substances, and is not suitable for making a molded article having a certain thickness porous. Further, when ultraviolet rays are used, the selectivity of the decomposition reaction of the polymer main chain is low, so that it is often difficult to cut the main chain of only one phase polymer out of the two-phase polymer.

On the other hand, β-rays, X-rays, γ-rays and the like penetrate deeper into the irradiation object, and have high selectivity for the decomposition reaction of the polymer main chain, high decomposition efficiency, and low cost. Very good. Particularly, β-rays (electron beams) that can be easily and inexpensively irradiated are most preferable. The irradiation amount of β-ray is not particularly limited, but is 100 Gy to 10 MGy, more preferably 1 KGy to 1 MGy, and most preferably 10 KGy.
y to 100 KGy. When the irradiation amount is too small, the decomposable polymer cannot be sufficiently decomposed.On the other hand, when the irradiation amount is too large, the decomposed product of the decomposable polymer is hardened by three-dimensional cross-linking or hardly decomposable polymer. There is a risk of decomposition.

The acceleration voltage varies depending on the thickness of the compact, that is, the length of penetration of β-rays into the compact.
20 kV to 2 MV for a thin film of about m, 100 μm
500 kV for films or bulk compacts
It is preferable to set it to about 10 MV. When the molded body contains a metal molded body or the like, the acceleration voltage may be further increased.

(B) The ratio of N / (Nc-No) of the monomer units constituting the polymer is 1.4 or more (however,
Is the total number of atoms in the monomer unit, Nc is the number of carbon atoms in the monomer unit, and No is the number of oxygen atoms in the monomer unit. Since these polymers have different dry etching resistances, the polymer of one phase can be selectively removed by dry etching.

Therefore, after forming a thin film of the above-mentioned polymer blend on a base, forming a phase-separated structure fixed in the nucleation and growth process in the thin film, the thin film is dry-etched to form at least one polymer phase. Selectively
The micropattern can be transferred by processing the base using the remaining polymer phase as a mask.

Hereinafter, the parameter N / (Nc-No) will be described in more detail. N is the total number of atoms per monomer unit (corresponding to a monomer unit) of the polymer, Nc is the number of carbon atoms, and No is the number of oxygen atoms. This parameter is an index indicating the dry etching resistance of the polymer. The larger the value, the higher the etching rate by dry etching (the lower the dry etching resistance). That is, the etching rate V
Between the _etch and the parameter, V _etch αN / (Nc
-No). This trend is due to Ar, O ₂ ,
It hardly depends on the type of various etching gases such as CF ₄ and H ₂ (J. Electrochem. Soc., 130, 143 (1983)).
As an etching gas, in addition to Ar, O ₂ , CF ₄ , and H ₂ described in the above literature, C ₂ F ₆ , CHF ₃ ,
CH ₂ F ₂ , CF ₃ Br, N ₂ , NF ₃ , Cl ₂ , CCl ₄ ,
HBr, SF ₆ or the like can be used. Note that the above parameters have no relation to the etching of inorganic substances such as silicon, glass, and metal.

When the specific parameter values are calculated,
As shown in the chemical formula, a polystyrene (PS) monomer
Knit is C₈H₈Therefore, 16 / (8-0) = 2
The monomer unit of polyisoprene (PI) is C_Five
H₈Therefore, 13 / (5-0) = 2.6.
The monomer unit of methyl methacrylate (PMMA)
C _FiveO_TwoH₈Therefore, 15 / (5-2) = 5. I
Therefore, in the PS-PMMA blend polymer, P
High etching resistance of S, only PMMA is etched
It can be expected that it is easy to be done. For example, CF_FourTraveling wave
150W, reflected wave 30W, flow rate 30sccm, pressure 0.
Reactive ion etching under 01 torr condition
(RIE), PMMA gives 4 ± 0.
It has been confirmed that it shows about three times the etching rate
You.

[0073]

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FIG. 3 shows N / (Nc-N) of various polymers.
o) shows the relationship between the value and the dry etching rate. The abbreviations used in FIG. 3 indicate the following polymers, respectively. S
EL-N = (Somer Industries, trade name), PMMA = polymethyl methacrylate, COP = glycidyl methacrylate-ethyl acrylate copolymer, CP-3 = methacrylate-t-butyl methacrylate copolymer, PB
= Polybenzyl methacrylate, FBM = polyhexafluorobutyl methacrylate, FPM = polyfluoropropyl methacrylate, PMIPK = polymethylisopropenyl ketone, PS = polystyrene, CMS = chloromethylated polystyrene, PαMS = polyα-methylstyrene, PVN = polyvinyl Naphthalene, PVB = polyvinyl biphenyl, CPB = cyclized polybutadiene.
As shown in this figure, V _etch @ N / (Nc-No)
It can be seen that the relationship holds.

In general, when an aromatic ring is contained, the ratio of carbon becomes relatively high because of containing a double bond, so that the value of the above parameter becomes small. As can be seen from the above parameters, the dry etching resistance increases as the amount of carbon in the polymer increases (the parameter value decreases), and the dry etching resistance decreases as the amount of oxygen increases (the parameter value increases). This can be qualitatively explained as follows. Carbon has low reactivity to radicals and is chemically stable. For this reason, if the polymer contains a large amount of carbon, it is difficult to react even if various radicals attack, so that the etching resistance is improved. On the other hand, since oxygen has high reactivity to radicals, if the amount of oxygen in the polymer is large, the etching rate is high and the etching resistance is low. Furthermore, if oxygen is contained in the polymer, oxygen radicals are likely to be generated. For example, when a fluorine-based etching gas such as CF ₄ is used, F radicals are multiplied by the action of oxygen radicals, and radicals involved in etching increase. Therefore, the etching rate increases. Since the acrylic polymer has a high oxygen content and a small number of double bonds, the value of the above parameter increases, and the acrylic polymer is easily etched.

As described above, the N / N ratio of the A polymer and the B polymer constituting the micropattern forming material of the present invention is described.
If the (Nc-No) parameter ratio is 1.4 or more,
A clear pattern is formed by etching. If the ratio is 1.5 or more, and more than 2, a large difference occurs in the etching rate between the two polymers, so that the stability during processing is improved. Also, the etching selectivity of the two types of polymers when actually dry-etched is 1.3 or more,
Further, it is preferably 2 or more, and more preferably 3 or more.

To improve the etching selectivity,
For example, when O ₂ or the like is used as an etching gas, it is particularly preferable to use a silicon-containing polymer as a polymer having high etching resistance and a halogen-containing polymer as a polymer having low etching resistance. The silicon-containing polymer is preferably poly (p-trimethylsilylstyrene) and the like, and the halogen-containing polymer is preferably a halogen-containing acrylic polymer such as poly (chloroethyl methacrylate).

(C) A case of using a polymer blend containing two or more polymers having different thermal decomposability at a temperature of 120 ° C. or higher will be described. When a polymer blend containing these polymers is heated above 120 ° C., at least one polymer does not thermally decompose, but at least one polymer is thermally decomposed and selectively removed.

Therefore, after forming a thin film of the above-mentioned polymer blend on an underlayer, forming a phase separation structure fixed in the nucleation and growth process in the thin film, the thin film is heated to 120 ° C. or more to form at least one kind of The micropattern can be transferred by selectively removing the polymer phase by thermal decomposition and processing the base using the remaining polymer phase as a mask.

The difference between the heat decomposition temperature of the heat-resistant polymer and the heat-decomposable polymer (the temperature at which the weight is reduced by half when heated under an inert gas stream of 1 atm for 30 minutes) is 20 ° C. or more, more preferably 50 ° C. As described above, it is most preferable that the temperature be 100 ° C. or higher. Further, it is more preferable that the heat-resistant polymer is one that three-dimensionally crosslinks at a temperature equal to or higher than the thermal decomposition temperature of the thermally decomposable polymer.

Examples of the thermally decomposable polymer chain include polyethers such as polyethylene oxide and polypropylene oxide, α-methylstyrene, acrylic resins such as polyacrylate and polymethacrylate, and polyphthalaldehyde.

Examples of the heat-resistant polymer include carbon-based polymers such as polyacrylonitrile, polymethacrylonitrile, polyimide, polyaniline derivative, polyparaphenylene derivative, and polycyclohexadiene derivative obtained by polymerizing a PPP monomer.

As the heat-resistant polymer, a polymer having a site where a side chain or a main chain is crosslinked by heat to form a heat-resistant molecular structure can also be used. For example, POSS (Polyhedral Oligomeric Silsesquio)
xane: a polymer having a siloxane cluster such as a polysiloxane T ₈ cube may be used. For example, a polymer obtained by polymerizing a methacrylate T ₈ cube represented by the following chemical formula is preferable.

[0084]

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(R represents H or a substituted or unsubstituted alkyl group, aryl group, or aralkyl group, such as methyl, ethyl, butyl, isopropyl, and phenyl).

As the heat resistant polymer, polysilane may be used. The polysilane is not particularly limited as long as it contains at least a polysilane structure having a repeating unit represented by the following chemical formula.

[0087]

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(R ¹ , R ² , R ³ and R ⁴ each independently represent a substituted or unsubstituted alkyl group, aryl group or aralkyl group having 1 to 20 carbon atoms).

The polysilane may be a homopolymer or a copolymer, and may have a structure in which two or more polysilanes are bonded to each other via an oxygen atom, a nitrogen atom, an aliphatic group, or an aromatic group. Specific examples of such polysilanes include, for example, poly (methylphenylsilane), poly (diphenylsilane), poly (methylchloromethylphenylsilane), poly (dihexylsilane), poly (propylmethylsilane), poly (dibutylsilane), Examples include poly (methylsilane), poly (phenylsilane), and the like, and random or block copolymers thereof.

(D) A polymer blend containing at least one kind of alkali-soluble polymer (including a polymer which can be changed from alkali-insoluble to alkali-soluble by some treatment) and at least one kind of alkali-insoluble polymer. thing. When a polymer blend containing these polymers is treated with an alkali developer, alkali-soluble polymers can be selectively removed.

Therefore, after forming a thin film of the above polymer blend on a base, forming a phase-separated structure immobilized during the nucleation and growth process in the thin film, the thin film is developed with an alkali developer to obtain an alkali-soluble polymer. Is selectively removed, and the micropattern can be transferred by processing the base using the remaining polymer phase as a mask.

Examples of the alkali-soluble polymers include novolak resins such as phenol novolak and naphthol novolak, main chain alicyclic polymers such as polyisobornene, polynorbornene, polycyclohexene, polycyclopentene and polycyclooctene, and hydroxyl groups, carboxyl groups and carbonyl groups. Those having a substituent introduced therein, polyhydroxystyrene, phenolic resin such as polyhydroxyvinylnaphthalene, polymethacrylic acid or polyacrylic acid and those having the α-position thereof substituted with halogen,
Examples include polyvinyl alcohol, polyvinyl acetate, and maleic anhydride.

Representative examples of the alkali-insoluble polymer include aromatic polymers such as polystyrene, rubber polymers such as polybutadiene and polyisoprene, and acrylic polymers such as polymethyl methacrylate. Most polymers are soluble in alkali. Many of them can be used as alkali-insoluble polymers because of their absence.

An alkali-insoluble resin can be obtained by introducing an alkali dissolution inhibiting group into an alkali-soluble polymer. Compounds used to introduce an alkali dissolution inhibiting group include ester groups such as t-butyl ester, isopropyl ester, ethyl ester, methyl ester, and benzyl ester; ethers such as tetrahydropyranyl ether; t-butoxy carbonate, methoxy Alkoxycarbonates such as carbonate and ethoxycarbonate; silyl ethers such as trimethylsilyl ether, triethylsilyl ether and triphenylsilyl ether; isopropyl ester, tetrahydropyranyl ester, tetrahydrofuranyl ester, methoxyethoxymethyl ester, 2-trimethylsilylethoxymethyl ester; 3-oxocyclohexyl ester, isobornyl ester, trimethylsilyl ester, triethyl Ryl ester, isopropyldimethylsilyl ester, di-t-butylmethylsilyl ester, oxazole, 2-alkyl-1,3-oxazoline, 4-alkyl-5-oxo-1,3-oxazoline, 5-alkyl-4-oxo- Esters such as 1,3-dioxolane; t-butoxycarbonyl ether, t-butoxymethyl tail, 4-pentenyloxymethyl ether, tetrahydropyranyl ether, tetrahydrothiopyranyl ether, 3-bromotetrahydropyranyl ether, 1-methoxycyclohexyl Ether, 4-methoxytetrahydropyranyl ether, 4-
Methoxytetrahydrothiopyranyl ether, 1,4-
Dioxan-2-yl ether, tetrahydrofuranyl ether, tetrahydrothiofuranyl ether, 2,
3,3a, 4,5,6,7,7a-octahydro-7,
8,8-trimethyl-4,7-methanobenzofuran-2
-Yl ether, t-butyl ether, trimethylsilyl ether, triisopropylsilyl ether, dimethylisopropylsilyl ether, diethylisopropylsilyl ether, dimethylsexylsilyl ether, t
Ethers such as -butyldimethylsilyl ether; methylene acetal, ethylidene acetal, 2,2,2
-Acetals such as trichloroethylidene acetal; ketals such as 1-t-butylethylidene ketal, isopropylidene ketal (acetonide), cyclopentylidene ketal, cyclohexylidene ketal, cycloheptyldenketal; methoxymethylene acetal, ethoxyethylene acetal , Dimethoxymethylene orthoester, 1-methoxyethylidene orthoester, 1-ethoxyethylidene orthoester, 1,
2-dimethoxyethylidene orthoester, 1-N, N
Cyclic orthoesters such as -dimethylaminoethylidene orthoester and 2-oxacyclopentylidene orthoester; silylketene acetals such as trimethylsilylketene acetal, triethylsilylketene acetal and t-butyldimethylsilylketene acetal; di-t- Butylsilyl ether, 1,3-
Silyl ethers such as 1 ', 1', 3 ', 3'-tetraisopropyldicycloxanylidene ether and tetra-t-butoxydisiloxane-1,3-diylidene ether; dimethyl acetal, dimethyl ketal, bis-
2,2,2-trichloroethyl acetal, bis-2,
Acyclic acetals and ketals such as 2,2-trichloroethyl ketal, diacetyl acetal and diacetyl ketal; 1,3-dioxane, 5-methylene-1,3-dioxane, 5,5-dibromo-1,3 −
Dioxane, 1,3-dioxolan, 4-bromomethyl-1,3-dioxolan, 4,3′-butenyl-1,3
-Dioxolane, 4,5-dimethoxymethyl-1,3
-Cyclic acetal and ketal such as dioxolane; O-trimethylsilyl cyanohydrin,
And cyanohydrins such as O-1-ethoxyethyl cyanohydrin and O-tetrahydropyranylcyanohydrin.

When using a polymer introduced with these alkali dissolution inhibiting groups, after forming a phase separation structure, a treatment for changing the alkali solubility while maintaining the structure is performed. An alkali-soluble polymer protected with an alkali dissolution inhibiting group easily becomes alkali-soluble because it undergoes a deprotection reaction in the presence of a catalyst such as an acid or an alkali. The solubility of the polymer in alkali can be adjusted by changing the degree of protection by the alkali dissolution inhibiting group between 0 and 100%.

In this case, when a photoacid generator which reacts to ultraviolet rays, X-rays, electron beams, etc. is used for the alkali-soluble polymer protected by the alkali dissolution inhibiting group, the alkali solubility of a specific site is increased by exposure. Can be controlled.
Examples of the photoacid generator include triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalene sulfonate, diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, bis (4-
tert-butylphenyl) iodonium triflate, bis (4-tert-butylphenyl) iodonium dodecylbenzenesulfonate, bis (4-tert
-Butylphenyl) iodonium naphthalene sulfonate, bis (4-tert-butylphenyl) iodonium hexafluoroantimonate, (hydroxyphenyl) benzenemethylsulfonium toluenesulfonate, 1- (naphthylacetomethyl) thiolanium triflate, cyclohexylmethyl (2- (Oxocyclohexyl) sulfonium triflate, dicyclohexyl (2-oxocyclohexyl) sulfonium triflate, dimethyl (2-oxocyclohexyl) sulfonium triflate, S- (trifluoromethyl) dibenzothiophenium trifluoromethanesulfonic acid, Se-
Iodonium salts such as (trifluoromethyl) dibenzothiophenium trifluoromethanesulfonic acid, I-dibenzothiophenium trifluoromethanesulfonic acid,
Onium salts such as sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, 1,2-naphthoquinonediazide-4-sulfonyl chloride, 2,3,4,4-
1,3-naphthoquinonediazido-4-sulfonic acid ester of tetrahydrobenzophenone and 1,3-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane
Diazoketone compounds such as diketo-2-diazo compounds, diazobenzoquinone compounds and diazonaphthoquinone compounds; 1,1-bis (4-chlorophenyl) -2,2,2
-Haloalkyl group-containing hydrocarbon compounds such as trichloroethane, phenyl-bis (trichloromethyl) -S-triazine, naphthyl-bis (trichloromethyl) -S-triazine, halogen-containing compounds such as haloalkyl group-containing heterocyclic compounds, 4-tris Β-ketosulfones such as phenacylsulfone, mesitylphenacylsulfone, and bis (phenylsulfonyl) methane; and sulfone compounds such as β-sulfonylsulfone.

Examples of the alkaline solution used as the developer include an aqueous solution of an inorganic alkali such as an aqueous solution of sodium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, an aqueous solution of tetramethylammonium hydroxide, An aqueous solution of an organic alkali such as an aqueous solution of trimethylhydroxyethylammonium hydroxide, an aqueous solution of ethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, pyrrole, piperidine, choline, etc. One to which an activator is added may be mentioned. The substrate and the polymer film after the development process are subjected to a rinsing process using water or the like, and further dried.

The phase separation structure of the present invention can be formed by the following method. Two or more incompatible polymers are dissolved in a suitable solvent to prepare a coating solution. The coating solution is applied on a substrate and dried to form a multi-component multi-phase polymer thin film. As a coating method, a method such as a spin coating method, a dip coating method, or a casting method can be used.

It is also possible to melt the blended polymer, apply it on a substrate and then cool it to form a phase-separated structure. A plurality of polymers may be melted and formed into a desired shape by a method such as a hot press method, an injection molding method, or a transfer molding method. After film formation or molding, by annealing at a temperature higher than the glass transition point of the polymer material, a better phase separation structure can be formed.

In the coating film forming process, an additive such as a dopant may be mixed into the coating solution. It is preferable to use, as such an additive, one having a specific affinity for one of the polymers that phase-separate from each other. In this case, when the phase separation structure is formed, the dopant can be easily localized only in the phase having good affinity.

As the additives, for example, Cr, V, Nb,
Ti, Al, Mo, Li, Lu, Rh, Pb, Pt, A
and a metal element such as u. These metal elements are
It can be used as a growth nucleus for a magnetic film of a magnetic recording medium or as an electrode material for a battery. You may use the additive which produces | generates the above-mentioned metal elements by reduction. Such additives include lithium 2,4-pentanedionate, lithium tetramethylheptanedionate, ruthenium 2,4-pentanedionate, magnesium 2,4-pentanedionate, magnesium hexafluoropentanedionate, magnesium Trifluoropentanedionate, manganese (II) 2,4-pentanedionate, molybdenum (V) ethoxide, molybdenum (VI) oxide bis (2,4-pentanedionate), neodymium 6,6
7,7,8,8,8-heptanefluoro-2,2-dimethyl-3,5-octandionate, neodymium hexafluoropentanedionate, neodymium (III)
2,4-pentanedionate, nickel (II) 2,4
-Pentanedionate, niobium (V) n-butoxide,
Niobium (V) n-ethoxide, palladium hexafluoropentanedionate, palladium 2,4-pentanedionate, platinum hexafluoropentanedionate, platinum 2,4-pentanedionate, rhodium trifluoropentanedionate, ruthenium (III ) 2,4-pentanedionate, tetrabutylammonium hexachloroplatinate (IV), tetrabromogold (II
I) Cetylpyridinium salt and the like.

The metal to be added as an additive may be ions or ultrafine particles of about several nm to several tens nm whose affinity for one phase is specifically enhanced by surface treatment. For example, metal fine particles whose surface is coated with the A polymer segregate in the A polymer phase, and metal fine particles whose surface is coated with the B polymer segregate in the B polymer phase. In this case, the surface-treated fine metal particles are deposited at a substantially central portion of a phase having a high affinity among the phases constituting the phase separation structure of the blend polymer. The metal fine particles whose surface is coated with the AB block copolymer precipitate at the interface between the A polymer phase and the B polymer phase. By using such a method, the same metal element can be intentionally precipitated in different phases. Even when such ultrafine particles are added to the coating solution, the ultrafine particles can be unevenly distributed only in a phase having a good affinity by the same coating operation as described above.

Instead of merely mixing the additives, they may be chemically bonded to the side chains or main chains of the polymer. In this case, by modifying only the polymer forming the specific phase with the functional molecular structure, the additive can be easily localized in the specific phase. In addition, by introducing a structure that is easily bonded to a specific additive into the main chain or side chain of the polymer, and before or after forming a phase separation structure, the additive is introduced into the polymer by contacting with the vapor or solution of the additive. May be. For example, if a chelate structure is introduced into a polymer, metal ions and the like can be added. The chelate structure may be introduced into the main chain, or may be introduced as a substituent at an ester site or the like of the polyacrylate. If a structure having ion exchange capability such as a pyridinium salt structure is introduced into the polymer, metal ions and the like can be added by counterion exchange.

When a plasticizer is added to the micropattern forming material of the present invention, a microphase-separated structure can be formed by annealing for a short time. The amount of the plasticizer is not particularly limited, but is 1 to 70% by weight, preferably 1 to 20% by weight, and more preferably 2 to 10% by weight, based on the blend polymer. If the amount is too small, the effect of accelerating the formation of the phase separation structure cannot be sufficiently obtained. If the amount is too large, the regularity of the phase separation structure tends to be disturbed.

As the plasticizer, aromatic esters and fatty acid esters are used. Specifically, phthalate ester plasticizers such as dimethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, and diisononyl phthalate; trimellitic acid plasticizers such as octyl trimellitate;
Pyromellitic acid plasticizers such as octyl pyromellitate; adipic acid plasticizers such as dibutoxyethyl adipate, dimethoxyethyl adipate, dibutyldiglycol adipate, and dialkylene glycol adipate are used.

As described above, when the blend polymer is phase-separated in the present invention, it is preferable to anneal at a temperature equal to or higher than the glass transition point. However, when this heat treatment is performed in an atmosphere containing oxygen or the like, the polymer is denatured and deteriorated by an oxidation reaction or the like, and a good microphase separation structure cannot be formed, or the heat treatment time becomes longer, Etch selectivity may not be obtained. In order to prevent such deterioration of the polymer, the heat treatment is preferably performed under anoxic conditions, preferably in a dark place where photodeterioration hardly occurs. However, annealing under oxygen-free conditions requires strict atmosphere control, which tends to increase manufacturing costs.

Therefore, it is preferable to add an antioxidant or a photodegradation inhibitor to the blend polymer. The antioxidant or photodeterioration agent is not particularly limited, but a radical trapping agent or the like for trapping radical species generated by an oxidation reaction or photodeterioration reaction is preferably used.

Specifically, for example, 3,5-di-tert-
Phenolic antioxidants such as butyl-4-hydroxytoluene, phosphorus antioxidants, sulfur antioxidants such as sulfide derivatives, bis (2,2,6,6-tetramethylpiperidinyl-4) sebacate, etc. HALS (Hindered Amine Light Stab) represented by piperidine compounds
(ilizer) -based light deterioration inhibitors, metal complex-based light deterioration inhibitors such as copper and nickel, and the like are used.

The amount of the antioxidant or photodeterioration agent is not particularly limited, but should be 0.01 to 10% by weight, 0.05 to 1% by weight, and 0.1 to 0.5% by weight. Is preferred. If the compounding amount is too small, the effect of preventing oxidation or the effect of preventing light deterioration is insufficient. If the amount is too large, the phase separation structure of the polymer may be disturbed.

By adding a cross-linking agent or introducing a cross-linkable group to the polymer, the polymers may be three-dimensionally cross-linked to each other after forming a phase-separated structure. Such cross-linking can further improve the thermal or mechanical strength of the phase separation structure, and can increase the stability. Considering durability such as heat resistance, each phase is preferably originally incompatible, but even if it is a phase-separated structure composed of non-incompatible phases, the polymer that forms the phase Can be cross-linked to improve durability.

In the present invention, using a pattern transfer technique, a pattern formed from a micropattern forming material composed of a polymer blend obtained by combining two or more polymers having a dry etching rate ratio of 1.3 or more is transferred to a substrate. Also, a pattern having a high aspect ratio can be obtained. The method of the present invention is a very effective technique because a recording medium or a display does not require much accuracy of the pattern position.

The pattern transfer is realized by combining the following layers. 1. Pattern forming film As the pattern forming film, as described above, a polymer obtained by mixing two or more polymers having a dry etching rate ratio of 1.3 or more, which forms a phase separation structure from nanometer to micron in a self-developing manner. Use a blend.

[0113] 2. Pattern transfer film The pattern transfer film is a layer provided below the pattern forming film and onto which a pattern formed on the pattern forming film is transferred. After the phase having low etching resistance in the polymer of the pattern forming film is etched, the pattern transfer film is subsequently etched. It is desirable to set the thickness and the etching rate of the pattern transfer film so that the etching is completed before the phase having high etching resistance in the pattern forming film is etched. For example, the pattern transfer film preferably has a dry etching rate ratio of 0.1 or more, more preferably 1 or more, more preferably 1 or more, as compared with a polymer having a low dry etching rate among blended polymers to be a pattern forming film. It is desirable that the number be 2 or more. As the pattern transfer film, A
metal thin film of u, Al, Cr, etc., polysilane, N / (N
An organic material having a value of c-No) larger than 3 and easy to be etched is desirable.

The polysilane used as the pattern transfer film may be any as long as it contains at least a part of a repeating unit represented by the following formula.

[0115]

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However, R ¹ and R ² each have 1-2 carbon atoms.
And 0 represents a substituted or unsubstituted alkyl group, aryl group or aralkyl group.

Specific examples of the polysilane include poly (methylphenylsilane), poly (diphenylsilane), and poly (methylchloromethylphenylsilane). The polysilane may be a homopolymer or a copolymer, or may have a structure in which two or more kinds of polysilanes are bonded to each other via an oxygen atom, a nitrogen atom, an aliphatic group, or an aromatic group. An organic silicon polymer obtained by copolymerizing polysilane and a carbon-based polymer may be used. The molecular weight of the polysilane is not particularly limited.
= 2000-1,000,000, and Mw = 3000-
Those having a range of 100,000 are preferred. If the molecular weight is too small, the coatability and etching resistance of the polysilane film will deteriorate. Further, when the pattern forming film is applied, the pattern forming film is redissolved, and there is a possibility that the pattern forming film and the polysilane film as the pattern transfer film are mixed. On the other hand, if the molecular weight is too high, the solubility of the polysilane in the coating solvent will decrease.

Since polysilane is easily oxidized and its etching characteristics are easily changed, it is preferable to add the above-described antioxidant or photodeterioration agent similar to that added to the micropattern forming material. The amount of these additives is not particularly limited, but may be 0.01 to 10 watts.
t%, and more preferably 0.05 to 2 wt%. If the addition amount is too small, the addition effect cannot be obtained, and if the addition amount is too large, the etching characteristics of polysilane may be deteriorated.

3. Lower Pattern Transfer Film The lower pattern transfer film is not necessarily provided, but if used, a pattern having a high aspect ratio can be formed. When the upper layer pattern transfer film is formed of a metal thin film or the like which is not easily etched by O ₂ , if the upper layer pattern transfer film is used as a mask and etched by O ₂ , a very deep hole can be formed in the lower layer pattern transfer film. Using this lower layer pattern transfer film as a mask, holes can be formed in the underlying substrate with a high aspect ratio. It is preferable that the material of the lower layer pattern transfer film has a dry etching resistance to a chlorofluorocarbon-based gas such as CF ₄ . Specifically, derivatives such as polystyrene and polyhydroxystyrene, polyvinyl naphthalene and derivatives thereof, and polymers such as novolak resins are used. Since these polymers do not need to have the same molecular weight, it is possible to select a relatively inexpensive resin that is easily produced industrially by a radical polymerization method or the like, and is advantageous in cost.

More specifically, a method of forming a lower and upper layer pattern transfer film and a pattern forming film on a substrate and performing etching three times to form a pattern will be described.

First, a polymer as described above is formed as a lower layer pattern transfer film on a substrate by a spin coating method, a dip method, or the like. It is desirable that the thickness of the lower layer pattern transfer film be equal to or greater than the depth of a hole or the like to be transferred. An inorganic film such as a metal or SiO is formed as an upper layer pattern transfer film on the lower layer pattern transfer film by a vacuum evaporation method, a plating method, or the like. The thickness of the upper layer pattern transfer film is desirably smaller than the thickness of the pattern forming film formed thereon. On the upper layer pattern transfer film,
The polymer blend of the present invention is formed as a pattern forming film. It is desirable that the thickness be substantially equal to the size of the structure to be formed.

The dry etching rate of the upper layer pattern transfer film is preferably higher than that of the pattern forming film. Specifically, the upper layer pattern transfer film is preferably etched at a rate of at least about 1.3 times, more preferably at least twice the rate of the pattern forming film. However, when a polymer film is provided as a lower layer pattern transfer film below the upper layer pattern transfer film, the above-described etching selectivity may not be satisfied. That is, after etching the upper layer pattern transfer film, the lower layer pattern transfer film can be etched with oxygen or the like. At this time, if the upper layer pattern transfer film has resistance to etching by oxygen, the lower layer pattern transfer film is easily etched by oxygen. In such a case, there is no problem even if the dry etching rate of the upper layer pattern transfer film is about 1/10 that of the pattern forming film.

After forming each film as described above, annealing is performed as necessary to form a microphase separation structure in the pattern forming film. Next, by performing RIE with a chlorofluorocarbon-based gas, at least one phase of the phase separation structure formed in the film is selectively removed to leave another phase. The upper layer pattern transfer film (for example, metal) is also etched to transfer a phase separation structure, for example, a sea-island structure, to this film.
Next, RIE is performed with oxygen or the like using the remaining upper layer pattern transfer film as a mask to etch the lower layer pattern transfer film (eg, polymer). When oxygen RIE is performed, the upper pattern transfer film made of a metal is not etched, and only the lower pattern transfer film made of an organic polymer is etched. Therefore, a structure having a very high aspect ratio can be formed. At the same time, the pattern forming film is ashed. Using the remaining lower layer pattern transfer film as a mask, RIE is performed again with a chlorofluorocarbon-based gas, and the substrate is etched. As a result, holes having an extremely high aspect ratio in the order of nanometer to micron can be formed in the base substrate.

Instead of the above method, the pattern forming film is irradiated with β-ray to cut the polymer main chain of at least one phase, and then the phase where the polymer main chain is cut is selectively removed by wet etching. Is also effective. By performing the same steps as above after this step, a pattern on the order of nanometers to microns can be formed on the substrate. In the above process, the RIE
Wet etching can be used instead of the step. However, the pattern shape is likely to collapse during the pattern transfer.

[0125]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. However, the present invention is not limited to only these examples.

Example 1 Low molecular weight polystyrene (P
S) (Mw = 2500) and polymethyl methacrylate (PMMA) (Mw = 5000) were mixed at a weight ratio of 80:20 to give a 10% by weight ethyl cellosolve acetate solution. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm. After evaporating the solvent at 110 ° C. for 90 seconds, annealing was performed at 210 ° C. for 10 minutes and then at 135 ° C. for 10 hours in a nitrogen atmosphere using an oven. These annealing temperatures are set higher than the glass transition temperatures of PS and PMMA.
210 ° C. is the temperature immediately before the decomposition of PMMA starts,
The short-time annealing at 210 ° C. flattens the film and can erase the history after spin coating. Also,
When annealing is performed at a temperature of about 135 ° C., phase separation proceeds efficiently, and a phase separation structure is formed. When observed in the phase mode of an atomic force microscope, the diameter of 1 μm
A structure in which some PMMA islands are scattered was confirmed.

This sample was subjected to CF ₄ , 0.01 to
Reactive ion etching (RIE) was performed under the conditions of rr, a traveling wave of 150 W, and a reflected wave of 30 W. Under these etching conditions, the etching rate of PS and PMMA constituting the phase separation film becomes 1: 4 or more, only the PMMA portion is selectively etched, and the exposed base is etched using the remaining PS pattern as a mask. Is done. Then, O ₂ , 0.01 torr was applied to this sample.
Ashing was performed under the conditions of r, a traveling wave of 150 W, and a reflected wave of 30 W to remove an organic substance (a mask made of PS). As a result, holes having a diameter of about 1 μm were formed at substantially equal intervals on the entire surface of the 3-inch SiO substrate.

Further, with respect to the above blend polymer,
10% by weight of dioctyl phthalate was added as a plasticizer, and the annealing conditions were 210 ° C. for 10 minutes, followed by 135 ° C.
A phase separation film was formed in the same manner as above except that the temperature was changed to 1 hour at ℃, and RIE was performed under the same conditions as above. as a result,
A hole pattern similar to the above was formed on the entire surface of the substrate.
As described above, by adding the plasticizer to the blend polymer, the annealing time could be significantly reduced.

[Embodiment 2] In the same manner as in Embodiment 1, 3
A phase separation film of a blend polymer was formed on a SiO substrate having an inch diameter. An acceleration voltage of 50 kV, 10
The entire surface is irradiated with an electron beam at a dose of 0 μC / cm ² ,
The main chain of MMA was cut. The phase separation film was developed with a developing solution for electron beam resist (a mixed solution of 3: 7 of MIBK and IPA) for 60 seconds, followed by rinsing with IPA to remove PMMA whose main chain was cut by the electron beam. Next, the substrate was etched with hydrofluoric acid for 1 minute using the remaining pattern mainly composed of PS as a mask. Thereafter, ultrasonic cleaning was performed in acetone to remove the remaining mask. As a result, holes having a diameter of about 1 μm were formed at substantially equal intervals on the entire surface of the 3-inch diameter SiO substrate.

A pattern was formed in the same manner as described above except that X-rays having a wavelength of 0.154 nm were irradiated at a dose of 1 J / cm ² instead of irradiating an electron beam. As a result, holes having a diameter of about 1 μm were formed at substantially equal intervals on the entire surface of the 3-inch diameter SiO substrate.

[Embodiment 3] PS and PM used in Embodiment 1
MA was mixed at a weight ratio of 20:80, and a phase separation film was formed on the magnetic film formed on the substrate having a diameter of 3 inches in the same manner as in Example 1. Irradiating this phase separation membrane with β-rays
The main chain of MMA was cut. This phase separation film is developed with a developing solution for an electron beam resist, and the P-chain whose main chain has been cut by β-rays is developed.
MMA was removed. Next, the magnetic film was etched with hydrochloric acid for 1 minute using the remaining PS-based pattern as a mask. Thereafter, ultrasonic cleaning was performed in acetone to remove the remaining mask. As a result, protrusion-like magnetic films having a diameter of 1 μm and a height of 100 nm were formed at substantially equal intervals on the entire surface of the substrate. Using this method, the magnetic film can be directly processed by a wet method and left in an island shape.

Example 4 A polystyrene film having a thickness of 5 μm was spin-coated as a lower layer pattern transfer film on a quartz substrate, and an aluminum film having a thickness of 100 nm was deposited thereon as an upper layer pattern transfer film. On this aluminum film, a phase separation film of the blend polymer was formed in the same manner as in Example 1.

This sample was subjected to CF ₄ , 0.01 to
RIE was performed under the conditions of rr, a traveling wave of 150 W, and a reflected wave of 30 W, and only the PMMA portion of the phase separation film was selectively etched. Further, the aluminum film was etched using the remaining PS as a mask. Then, O
₂ , 0.01 torr, traveling wave 150W, reflected wave 30W
Ashing was performed under the conditions described above to remove the remaining PS mask and the polystyrene film exposed at the portion where the aluminum film was etched. Again with this sample, CF ₄ , 0.01 torr, traveling wave 150 W,
RIE was performed under the condition of a reflected wave of 30 W, and the aluminum film as the upper layer pattern transfer film and the exposed quartz substrate were etched. Again with this sample, O ₂ , 0.01 torr, traveling wave 150 W, reflected wave 30
Ashing was performed under the condition of W to remove the remaining polystyrene film. As a result, an average diameter of 1 μm
A hole having a very high aspect ratio of 5 m was formed.

Example 5 Low molecular weight polystyrene (P
S) (Mw = 2500) and polyhydroxystyrene (P
HS) (Mw = 5000) were mixed at a weight ratio of 80:20 to give a 10% by weight propylene glycol monoethyl ether acetate (PGMEA) solution. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm. After evaporating the solvent at 110 ° C. for 90 seconds, it was heated at 210 ° C. for 1 second in a nitrogen atmosphere using an oven.
Annealing was performed for 0 minute and then at 160 ° C. for 10 hours.
When observed in the phase mode of an atomic force microscope, a structure in which PHS islands having a diameter of about 1 μm were scattered in the sea of PS was confirmed.

This sample was treated with an alkaline developer (tetramethylammonium hydroxide: 2.38% by weight of TMAH).
Aqueous solution) for 60 seconds. As a result, the portion of PHS soluble in the alkali developer was selectively removed.

[0136] CF ₄ , 0.01 to
Reactive ion etching (RIE) was performed under the conditions of rr, traveling wave 150 W, and reflected wave 30 W, and the remaining PS
The exposed base was etched using the pattern of No. 1 as a mask. Then, O ₂ , 0.01 torr was applied to this sample.
Ashing was performed under the conditions of r, a traveling wave of 150 W, and a reflected wave of 30 W to remove an organic substance (a mask made of PS). As a result, holes having a diameter of about 1 μm were formed at substantially equal intervals on the entire surface of the 3-inch SiO substrate.

When the substrate on which the PS pattern is formed is etched with a 1% hydrofluoric acid aqueous solution using the PS pattern as a mask, holes having a diameter of about 1 μm are formed at substantially equal intervals on the entire surface of the substrate. Could be formed.

Example 6 Polystyrene (PS) (Mw
= 2500) and polyethylene oxide (PEO) (Mw
= 10000) in a weight ratio of 80:20, and the whole is 1
A 0% by weight cyclohexane non-solution was obtained. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm. After evaporating the solvent at 110 ° C. for 90 seconds, annealing was performed at 100 ° C. for 10 hours in a nitrogen atmosphere using an oven. Again, it was baked at 150 ° C. for 1 hour using an oven. As a result, it was confirmed that the PEO portion was decomposed and holes were formed in the polystyrene portion. The polystyrene was heated to a temperature higher than the glass transition temperature and softened, but the shape of the hole was preserved.

This sample was subjected to CF ₄ , 0.01 to
Reactive ion etching (RIE) was performed under the conditions of rr, traveling wave 150 W, and reflected wave 30 W, and the remaining PS
The exposed base was etched using the pattern of No. 1 as a mask. Then, O ₂ , 0.01 torr was applied to this sample.
Ashing was performed under the conditions of r, a traveling wave of 150 W, and a reflected wave of 30 W to remove an organic substance (a mask made of PS). As a result, holes having a diameter of about 1 μm were formed at substantially equal intervals on the entire surface of the 3-inch SiO substrate.

Example 7 Polystyrene (PS) (Mw
= 6000) and polytert-butyl methacrylate (PtBMA) (Mw = 4800) in a weight ratio of 72:28.
, And 1% by weight of triphenylsulfonium triflate was added to the polymer to give a 10% by weight ethyl cellosolve acetate solution. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm, and the solvent was evaporated at 110 ° C. for 90 seconds.

Using a mask in which a pattern was drawn with chromium on a quartz substrate, contact exposure was performed with ultraviolet light having a wavelength of 252 nm from a mercury lamp. This was baked at 150 ° C. for 10 minutes. The tertiary butyl of PtBMA was removed only in the exposed portion by baking, and changed to polymethacrylic acid (PMA).

This was annealed at 210 ° C. for 4 hours in a nitrogen atmosphere using an oven. When observed in the phase mode of an atomic force microscope, a structure in which PMA islands having a diameter of about 0.7 μm were scattered in the sea of PS was confirmed.

This sample was washed with an alkaline developer (tetramethylammonium hydroxide: 2.38 wt% of TMAH).
Aqueous solution) for 60 seconds. As a result, the PMA portion soluble in the alkali developer was selectively removed. In addition,
The unexposed portion showed a phase separation pattern, but was not dissolved in the alkali developing solution.

This sample was subjected to CF ₄ , 0.01 to
Reactive ion etching (RIE) was performed under the conditions of rr, traveling wave 150 W, and reflected wave 30 W, and the remaining PS
The exposed base was etched using the pattern of No. 1 as a mask. Then, O ₂ , 0.01 torr was applied to this sample.
Ashing was performed under the conditions of r, a traveling wave of 150 W, and a reflected wave of 30 W to remove an organic substance (a mask made of PS). As a result, holes having a diameter of about 0.7 μm were formed at substantially equal intervals only in the exposed portions on the 3-inch SiO substrate.

When the substrate on which the PS pattern was formed was etched with a 1% hydrofluoric acid aqueous solution using the PS pattern as a mask, a hole having a diameter of about 1 μm was formed only in the exposed portion of the substrate. It could be formed at substantially equal intervals.

Further, with respect to the above blend polymer,
A phase separation film was formed in the same manner as described above, except that 10% by weight of dioctyl phthalate was added as a plasticizer and the annealing conditions were set at 210 ° C. for 1 hour, and RIE was performed under the same conditions as above. As a result, the same hole pattern as described above could be formed on the substrate. As described above, the addition of the plasticizer to the blend polymer significantly reduced the annealing time.

[Embodiment 8] An example of manufacturing a field emission display (FED) element shown in FIG. 4 will be described. Niobium (N) is placed on an insulating substrate 101 such as glass.
b), molybdenum (Mo) or aluminum (Al)
The cathode conductor 102 made of a metal thin film is formed.
A portion of the cathode conductor 102 is etched by photolithography to form a hollow portion having a side of about 40 to 100 μm. In order to cover the cathode conductor 102, a thickness of 0.
The resistance layer 103 having a thickness of about 5 to 2.0 μm is formed. As a material of the resistance layer 103, In ₂ O ₃ , Fe ₂ O ₃ , Zn
O, NiCr alloy or silicon doped with impurities is used. The resistivity of the resistance layer 103 is about 1 × 10
It is preferably set to ¹ to 1 × 10 ⁶ Ωcm.

The resistance layer 103 is patterned by wet etching using an alkaline solution such as ammonia or reactive ion etching (RIE) using a fluorine-based gas to form a plurality of terminal portions 103A. Next, an insulating layer 104 made of silicon dioxide having a thickness of about 1.0 μm is formed so as to cover the cathode conductor 102 and the resistance layer 103 by a sputtering method or a CVD method. further,
A film thickness of about 0.4 μm is formed on the insulating layer 104 by a sputtering method.
A gate conductor 105 made of m, such as Nb or Mo, is formed.

Next, the intersection of the gate wiring and the emitter wiring is formed by a resist (OFPR800, 100c manufactured by Tokyo Ohka).
Protected by p) patterning. Subsequently, according to the method of the fifth embodiment, the solution of the blended polymer is spin-coated on the gate conductor 105 and dried, and then annealed to form a polymer phase separation film. The polymer phase separation film is subjected to RIE using CF ₄ gas, selectively etching only the PMMA portion of the phase separation film, and further etching the gate conductor 105 using the remaining PS pattern as a mask. Transfer the pattern. afterwards,
Ashing is performed with an O ₂ asher to remove remaining organic substances. Thus, the gate conductor 105 has a diameter of about 840.
A large number of openings 106 of nm are formed. Wet etching using buffered hydrofluoric acid (BHF) or CH
The insulating layer 104 in the opening 106 is removed by RIE using a gas such as F ₃ until the resistance layer 103 is exposed.

Next, a peeling layer is formed by obliquely depositing aluminum using an electron beam (EB) evaporation method. Molybdenum is vapor-deposited vertically on the release layer by EB vapor deposition, and molybdenum is deposited in a cone shape in the opening 106 to form the emitter 107. After that, the release layer is removed with a release liquid such as phosphoric acid to produce an FED element as shown in FIG.

[Embodiment 9] An example of manufacturing the FED element shown in FIG. 5 will be described. 14 inches diagonal, thickness 5 mm
Was cleaned and its surface was roughened by plasma treatment. This glass substrate 20
1, an emitter wiring 2 having a width of 350 μm in parallel with the long side direction.
02 was produced at a pitch of 450 μm. At this time, the substrate 20
A region of 2 inches each from both sides parallel to the direction of one emitter wiring 202 was used as a wiring margin, and patterning was performed so that the emitter wiring 202 was not formed in this region. Specifically, a PVA film was applied, exposed (photopolymerized) with a UV-ray through a mask, developed, and patterned to leave a PVA film in a region between the emitter wires 202. The patterning accuracy at this time was 15 μm. 50 nm by electroless plating
After growing the Ni film, the PVA film and the Ni film
The membrane was lifted off. Using the remaining Ni film as an electrode, a 1 μm Au film was grown by electrolytic plating.

A SiO ₂ film 2 as an insulating layer by the LPD method
03 was grown at 1 μm. Although this SiO ₂ film 203 contained many particle defects, its density was 1%.
The number was about 1000 pieces per square cm, which was a level having no practical problem. Although the film formed on Au was slightly darkened, the withstand voltage was 100 V per 1 μm, which was a practically acceptable level. This SiO ₂ film 203
Covered the step portion of the Au—Ni wiring conformally, and there was no Au exposed portion. After growing a 30 nm Pd film on the SiO ₂ film 203 by electroless plating, a 200 nm Ir film was grown by electrolytic plating to form a gate film. Next, the gate film is patterned in the short side direction of the substrate to form a gate wiring 2 having a width of 110 μm.
04 at a pitch of 150 μm. At this time, the substrate 20
Areas of 2 inches each from both sides parallel to the direction of one gate wiring 204 are used as wiring margins, respectively.
In this region, patterning was performed so that the gate wiring 204 was not formed. Specifically, as described above,
A film was applied, exposed (photopolymerized) with ultraviolet light through a mask, and developed, patterned to leave a PVA film on the gate wiring 204, and the remaining exposed area was removed by etching. At this time, the patterning accuracy was 15 μm.

Next, a part of the gate wiring 204 and the SiO ₂ film 203 was removed until the emitter wiring 202 was exposed, and patterning was performed to provide a substantially circular opening 205. There are two reasons why the patterning of the gate wiring 204 and the patterning of the opening 205 are performed separately.
One is that since the diameter of the opening 205 is about 1 μm, it is necessary to use a patterning method having an optical resolution of about 1 μm. The other is the opening 205
This is because it is not always necessary to arrange them in an orderly manner, as long as there are approximately equal numbers of openings 205 having an almost uniform opening diameter in each pixel.

Specifically, the opening 205 is formed as follows.
Was patterned. Polystyrene (PS) (M
w = 6000 and polytert-butyl methacrylate (PtBMA) (Mw = 4800) in a weight ratio of 72:
28, and 1.5% by weight of naphthylimide / triflate was added to the polymer.
Was made into a solution of ethyl cellosolve acetate and filtered. This solution was spin-coated on the gate wiring 204 and dried at 110 ° C. to form a 970 nm-thick polymer film. Except for the intersection of the gate wiring 204 and the emitter wiring 202, only the region where the opening 205 was formed was exposed to g-line to generate an acid from the photoacid generator. Anneal at 150 ° C. for 1 hour in an oven in a nitrogen atmosphere to form a phase separation film and expose poly-t-
Butyl acrylate was decomposed by acid to polyacrylic acid. As a result of the reflow during annealing, the thickness of the polymer film on the gate wiring 204 was 1 μm. The entire substrate is immersed in an alkaline solution for 3 minutes to remove polyacrylic acid "islands" and rinsed with pure water.
The gate wiring 204 was exposed. The gate wiring 204 was etched by RIE, and the SiO ₂ film 203 thereunder was further etched to expose the emitter wiring 202.

Next, a resistive layer 206 was formed in the opening 205 by electrophoresis. This operation was performed by dividing the emitter wiring by 100 lines. As a material of the resistance layer 206, a mixture of polyimide fine particles having a particle diameter of 100 nm (manufactured by PII Research Institute) and carbon fine particles containing fullerene having a particle diameter of 10 nm in a weight ratio of 1000: 1 was used. 0.4 wt% of this mixture was dispersed in a dispersion solvent (Isoper L, manufactured by Exxon Chemical). In addition, zirconium naphthenate (manufactured by Dainippon Ink and Chemicals, Inc.) as a metal salt was added at 10 wt% to the polyimide / carbon fine particle mixture.
% Was added. The substrate 201 is immersed in the dispersion,
The counter electrodes were arranged at an interval of 1 to 100 μm, the emitter wiring 202 was grounded, and +100 V was applied to the counter electrodes while applying ultrasonic waves. Immediately after the application of the voltage, a current of several mA began to flow, but the current exponentially decayed, and was not observed after 2 minutes. At this point, the resistive material dispersed in the dispersion solvent was all deposited on the substrate 201. Subsequently, the opposite substrate is grounded, and +
By applying a voltage of 50 V, the fine particles adhering to the gate wiring 204 were removed by electrophoresis in a solvent. Further, annealing was performed at 300 ° C. in a nitrogen atmosphere to fix the resistance layer 206 to the emitter wiring 202.

Next, a fine particle emitter layer 207 was deposited by electrophoresis in the same manner as described above. Particle emitter layer 2
As material No. 07, cubic boron nitride fine particles having a particle diameter of 100 nm (product name SBN-B, manufactured by Showa Denko KK) were prepared. After dilute hydrofluoric acid treatment of the BN fine particles, hydrogen plasma treatment was performed at 450 ° C. 0.2% by weight of these BN fine particles were dispersed in the same solvent used for depositing the resistance layer. Further, zirconium naphthenate is added at 10 wt% to BN fine particles.
Was added. After the BN particles were started in the same manner as above, the particles adhered on the gate wiring 204 were removed.
Further, the fine particle emitter layer 207 was fixed to the resistance layer 206 by annealing at 350 ° C. in a hydrogen atmosphere.

A face plate 211 on which an anode electrode layer 212 made of ITO and a fluorescent layer 213 were formed was attached to the obtained electron-emitting device array via a spacer 208 having a height of 4 mm, and the inside of a vacuum chamber was installed. installed. The pressure inside the vacuum chamber was reduced to 10 ^-6 Torr by a turbo molecular pump. Anode potential of 35
It was set to 00V. Both the non-selected emitter wiring 202 and the gate wiring 204 were set to 0V. Each of the selected emitter wiring 202 and gate wiring 204 is
Biased to 15V, + 15V. As a result, electron emission occurred, and a bright spot was confirmed on the fluorescent layer 213. Select multiple pixels across the display area,
The luminance was measured under the same conditions. As a result, the variation in luminance was within 3%.

[0158]

As described above in detail, according to the present invention, there is provided a material and a method which can easily form a pattern of nanometer to micron order having considerable regularity by utilizing the phase separation of a blended polymer. Can be provided.

[Brief description of the drawings]

FIG. 1 is a phase diagram of a blend polymer.

FIG. 2 is a photograph showing phase-separated structures with various compositions for a blend polymer of polystyrene and poly-2-chlorostyrene.

FIG. 3 is a graph showing a relationship between N / (Nc-No) values of various polymers and a dry etching rate.

FIG. 4 is a cross-sectional view of a field emission display manufactured in an example of the present invention.

FIG. 5 is a sectional view of another field emission display manufactured in the embodiment of the present invention.

[Explanation of symbols]

101 ... insulating substrate 102 ... cathode conductor 103 ... resistive layer 104 ... insulating layer 105 ... gate conductor 106 ... opening 107 ... emitter 201 ... glass substrate 202 ... emitter wiring 203 ... SiO ₂ film 204 ... gate wiring 205 ... opening 206 ... Resistive layer 207 Fine particle emitter layer 208 Spacer 211 Face plate 212 Anode electrode layer 213 Fluorescent layer

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yasuyuki Hotta 1 Kosaka Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa F-term in the Toshiba R & D Center (reference) 2H025 AA02 AB14 AB16 AB17 AC03 AC05 AC06 BE01 BE07 BE08 BE10 BF03 BF05 BF09 BF12 BF14 BH04 BJ01 CB16 CB41 CB52 CC01 CC05 CC17 CC20 DA40 FA01 FA17 FA20 FA21 4J002 BB03X BB12W BB12X BB18W BC03X BC09W BG01W BG01X BG03X BG04W BG06W FD08 BG06W FD03

Claims (5)

[Claims] 1. A polymer blend comprising, on a substrate, at least one polymer having hydrogen at the α-position carbon of the monomer unit and at least one polymer having an alkyl group or halogen at the α-position carbon of the monomer unit. Forming a thin film of a micro-pattern forming material, forming a phase-separated structure in the thin film, and irradiating the thin film with a high-energy ray to cut at least one polymer main chain, A method for forming a micropattern, comprising: a step of selectively removing a polymer phase in which the main chain has been cut; and a step of processing a base using the remaining polymer phase as a mask. 2. The method according to claim 1, wherein the ratio of N / (Nc-No) of the monomer units constituting the polymer is 1.4 or more (where N is the total number of monomer units and Nc is the number of carbon atoms of the monomer units). , No is the number of oxygen atoms in the monomer unit) forming a thin film of a micropattern-forming material comprising a polymer blend containing two or more polymers, and forming a phase-separated structure in the thin film; A method for forming a micro pattern, comprising: a step of selectively removing at least one kind of polymer phase by etching a thin film; and a step of processing a base using the remaining polymer phase as a mask. 3. A step of forming a thin film of a micropattern forming material comprising a polymer blend containing two or more polymers having mutually different thermal decomposabilities at a temperature of 120 ° C. or more at a temperature of 120 ° C. or more; A step of forming an isolation structure, a step of heating the thin film to 120 ° C. or more to selectively decompose and remove at least one polymer phase, and processing a base using the remaining polymer phase as a mask And a step of forming a micro pattern. 4. The method according to claim 1, wherein at least one alkali-soluble substrate is provided on the substrate.
Forming a thin film of a micropattern-forming material comprising a polymer blend containing a seed polymer and at least one alkali-insoluble polymer; forming a phase-separated structure in the thin film; A method for forming a micropattern, comprising: a step of selectively removing an alkali-soluble polymer phase by developing with a liquid; and a step of processing a base using the remaining polymer phase as a mask. 5. A step of forming a pattern transfer film on a base, and a step of forming a thin film of the micropattern forming material according to claim 1, 2, 3 or 4 on the pattern transfer film. Forming a phase separation structure in the thin film, selectively removing at least one polymer phase from the thin film, and etching the pattern transfer film using the remaining polymer phase as an etching mask. A step of transferring the pattern of the phase separation structure to the pattern transfer film, and a step of transferring the pattern of the phase separation structure to the base by etching the base using the pattern transfer film to which the pattern of the phase separation structure is transferred as an etching mask. And a method for forming a micro pattern.