JP3515445B2 - Method of forming micro patterns - Google Patents

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 of nanometer to micron order on an underlayer in a self-organizing manner and using this as a mask to form a highly regular micropattern on the underlayer. In addition, the present invention forms a structure of nanometer to micron order in bulk in a self-organizing manner and uses it as a highly ordered microstructure as it is, or uses this as a template for other highly ordered microstructures. A material capable of forming The material of the present invention is a hard disk, solar cell, photoelectric conversion element, light emitting element, display, light modulation element, organic FET.
It is applied to the manufacture of devices and capacitors.

[0002]

2. Description of the Related Art As the performance of electronic parts has become more sophisticated, the need for fine patterns and structures has been increasing. For example, fine processing technology is required for LSIs and liquid crystal displays. Many devices, such as batteries and capacitors, require a large surface area in a small volume. In the future, high-density 3D packaging technology will also be required. Various techniques are used for these processes, but the more minute the processes, the higher the manufacturing cost.

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

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 patterns of about m. However, in order to form a nanoscale pattern close to the optical resolution limit by lithography, it is necessary to use a very expensive exposure apparatus. Further, since the resist has low stability against the atmosphere, it is necessary to take measures such as mounting a chemical filter in order to manage the atmosphere in the clean room. Therefore, enormous investment is required for the method of forming a fine pattern by lithography.

On the other hand, patterning on the order of nanometers to microns is required, but there are some fields in which precision such as lithography is not required. However, since no simple method has been known so far, even in such a field, a fine pattern has to be formed by a method such as lithography using an electron beam or deep ultraviolet rays. As described above, such a technique cannot avoid the problem that the smaller the processing size, the more complicated the operation becomes and the huge investment is required.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a material and method capable of easily forming a nanometer to micron order pattern having a considerable regularity by utilizing phase separation of a blend polymer. Especially.

[0007]

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

Specific examples of the micropattern forming material of the present invention include the following.

(A) A micro-structure comprising 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. Patterning material.

(B) The N / (Nc-No) ratio 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), which is 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 different thermal decomposition properties at a temperature of 120 ° C. or higher.

(D) A micropatterning 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, the following method can be mentioned as a method of forming a micro pattern using the above-mentioned micro pattern forming material.

The first method for forming a micropattern according to the present invention comprises at least one type of polymer having hydrogen on the α-position carbon of the monomer unit and at least 1 polymer having an alkyl group or halogen on the α-position carbon of the monomer unit on the underlayer.
Forming a thin film of a micro-pattern forming material comprising a polymer blend containing one kind of polymer, forming a phase-separated structure in the thin film, and irradiating the thin film with a high energy ray to form at least one kind of polymer. The method comprises 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 underlayer using the remaining polymer phase as a mask. To do.

The second method of forming a micropattern according to the present invention is the method of forming N of a monomer unit constituting a polymer on an underlayer.
Two or more polymers having a ratio of / (Nc-No) of 1.4 or more (where N 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). Forming a thin film of a micropatterning 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 the underlayer using the remaining polymer phase as a mask. It is characterized by having.

The third method for forming a micropattern of the present invention is a method for forming a thin film of a micropattern forming material comprising a polymer blend containing two or more kinds of polymers having different thermal decomposition properties at a temperature of 120 ° C. or more on a base. A step of forming, a step of forming a phase-separated structure in the thin film, and a step of heating the thin film to 120 ° C. or higher to selectively thermally decompose and remove a phase of at least one polymer, which remained. And a step of processing the underlayer using the polymer phase as a mask.

A fourth method for forming a micropattern of 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 the underlayer. A step of forming a phase-separated structure in the thin film, a step of selectively removing the alkali-soluble polymer phase by developing the thin film with an alkali developing solution, the remaining polymer phase And a step of processing the base as a mask.

The method of forming a micropattern by pattern transfer according to the present invention comprises 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 micropattern forming materials on the pattern transfer film. A step of forming a phase separation structure in the thin film, a step of selectively removing at least one polymer phase from the thin film, and the pattern transfer film being etched using the remaining polymer phase as an etching mask. Transferring the pattern of the phase separation structure to the pattern transfer film, and etching the base using the pattern transfer film having the pattern of the phase separation structure transferred as an etching mask to transfer the pattern of the phase separation structure to the base. And a step of performing To.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. The phenomenon commonly called polymer phase separation is 2
There are macro phase separation, which is phase separation between polymer molecules of more than one species, and micro phase separation, which is phase separation within molecules observed in block copolymers and graft copolymers. In the present invention, unless otherwise specified, the phase separation means macro phase separation which is phase separation between polymer molecules. In the macro phase separation, the scale of fluctuation occurrence is about 1 μm, and thus a phase separation structure larger than the μm order is formed in principle. However, since the two types of polymer chains can be completely separated by macro phase separation, it is possible to completely separate the two after a long time.
Divide into phases. However, not all blend polymers undergo phase separation, and the conditions of the blend polymer capable of forming a phase separation structure having a relatively highly ordered 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 the horizontal axis and the temperature as the vertical axis. The composition corresponding to the region where the phase separation occurs through the nucleation and growth process, and is sandwiched between the binodal curve that is the boundary between the multiphase state and the spinodal curve that is the boundary that causes the phase separation after spinodal decomposition. Have. This will be described with reference to FIG.

FIG. 1 shows an example of a UCST (upper critical eutectic temperature) type phase diagram of a blend polymer comprising 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 (a binode curve). In the area above this curve, the two polymers are completely mixed into a one-phase state, and in the area below this curve, the two 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 blend polymer having a predetermined composition. The broken line is called a spinodal curve (cusp curve), and in the region below this curve, the two polymers undergo spinodal decomposition and undergo phase separation. On the other hand, in the region sandwiched between the binodal curve and the spinodal curve (hatched region in FIG. 1), the two kinds of polymers undergo phase separation through the nucleation and growth process, and finally two phases are completely formed. However, considerable regularity is observed in the nucleation and growth process. In addition, LCST
In the (lower critical eutectic temperature) type phase diagram, the top and bottom of the phase diagram with respect to temperature are reversed from those in FIG. 1, and the above relationship with temperature is exchanged.

FIG. 2 shows an example of polystyrene and poly 2-.
Blend polymer with chlorostyrene (PS / P2Cl
S) shows the phase-separated structure in various compositions (Polymer Society, edited by Polymer Alloy, Tokyo Kagaku Dojin, 199).
3). As shown in this figure, it can be seen that various forms can be adopted depending on the composition ratio of the A polymer and the B polymer. When the composition ratio 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 lower than the glass transition temperature during this process, the phase separation is stopped and the structure is fixed. In addition, the structure may be fixed even when the viscosity is sufficiently high.
On the other hand, when the composition ratio of the two phases is around 7: 3 to 1: 1, spinodal decomposition generally occurs and a three-dimensional intricate structure is formed, so regularity is not recognized.

In the present invention, a blended polymer having a composition corresponding to the shaded area in FIG. 1 at a predetermined temperature is used, and a regular pattern in the nucleation and growth process (for example, two dots at both ends of FIG. 2) is used. Pattern) is used to form a micropattern by various methods, as described in detail later.

Next, the thermodynamic conditions for phase separation of the blend polymer will be described. The phase separation of the blended polymer is performed through a process in which the blended polymer is melted, annealed at a temperature not lower than the glass transition temperature and not higher than the phase transition temperature to form a phase separated structure, and then the phase separated structure is fixed at room temperature. It Alternatively, the phase-separated structure can be formed by dissolving the blend polymer in a solvent and 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-separated structure having considerable regularity.

Regarding the conditions for causing the phase separation of the blended polymer, the thermodynamics at the above annealing may be considered.
According to the Flory-Haggins theory, the following free energy of mixing ΔG must be positive for the phase separation of the two A and B polymers.

[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 A polymer, χ is the interaction parameter between A polymer and B polymer, 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 kinds of polymer chains are mixed with each other, and when it 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 (polymerization degree) increases, the negative value decreases and approaches 0, which is advantageous for phase separation. The third term is the enthalpy term, 2
It represents the repulsive force of the polymer chains of the species.

The composition corresponding to the region sandwiched between the above-mentioned binodal curve and spinodal curve is
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, and it becomes difficult for them to be compatible with each other, and phase separation is likely to occur. χ is a function that depends on temperature and is represented by the following equation.

[0031]

[Equation 2]

Χ can be obtained experimentally,
The experiment involves considerable difficulty. For the χ parameter of typical polymer combinations, see Polymer Handbook
(John Wiley & Sons 1999) etc. As an alternative to this, the interaction parameter χ is approximately represented by the following relational expression using a commonly known value called the solubility parameter δ.

[0033]

[Equation 3]

If the difference between the solubility parameters of the two polymers is known based on the equations (3) and (1), it can be predicted before mixing if a certain blend polymer undergoes phase separation. The standard for the blend polymer to cause phase separation is 2
The solubility parameter of the seed polymer is 1 cal ^0.5 / cm
The difference is ^1.5 or more. On the other hand, if the difference in the solubility parameter is too large, it becomes difficult to mix the two polymers, so the difference in the solubility parameter between 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.

Further, as described above, the larger the degree of polymerization of the polymer is, the more easily phase separation occurs, but conversely, when the molecular weight becomes small, phase separation does not occur. However, if the molecular weight of the polymer is too large, it becomes difficult to mix the two types of polymers. Therefore, the molecular weight of the polymer is preferably 100,000 or less, more preferably 30,000 or less. This is N in equation (1)
_{This is because A} and / or N _B are increased, ΔG is increased, and the repulsive force between the polymers is increased. In particular, in order to proceed the phase separation through the nucleation and growth process, the molecular weight of the polymer constituting the polymer blend of the present invention is
The weight average molecular weight of both A polymer and B polymer is 5000.
The optimum value is about 10,000.

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

[0037]

[Equation 4]

From the formula (4), the minimum molecular weight of the blend polymer composed of the A polymer and the B polymer can be determined. On the contrary, from this formula, when the molecular weight of the blend polymer is determined, the combination of the A polymer and the B polymer can be selected. Further, from this equation, it is understood 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 may be difficult to form a sea-island structure having a biased composition and particularly small biased composition islands.

Further, in order to obtain a phase-separated structure having a uniform structure size, a copolymer such as a block copolymer, a graft copolymer or a random copolymer may be blended to adjust the composition ratio. At this time, if there is an excessive difference in solubility between the two polymers, phase separation between the copolymer and the homopolymer may occur. In order to avoid this phase separation as much as possible, it is preferable to lower the molecular weight of the homopolymer. For example, when an AB copolymer is added to the A homopolymer and the B homopolymer, if the molecular weight of the homopolymer is decreased, the negative value of the entropy term of the Flory-Huggins equation becomes large, and the AB copolymer and both homopolymers are increased. This is because and become easy to mix. Further, the molecular weight of the A homopolymer is preferably smaller than that of the A block of the AB copolymer. The same applies to the B homopolymer. Considering thermodynamic stability, the molecular weights of A homopolymer and B homopolymer are the same as those of A-B copolymer.
More preferably, it is less 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 1000, it may be dissolved in the B block of the AB copolymer, which is not preferable. The same applies to the B homopolymer. In consideration of the glass transition point, the molecular weight is more preferably 3000 or more.

The solvent that dissolves the blend polymer is preferably a good solvent for the two polymers that make up the blend polymer. This is because the repulsive force between polymer chains is proportional to the square of the difference between the solubility parameters of two polymer chains, as shown in equation (3). Therefore, the difference between the solubility parameters is reduced to minimize the free energy of the system. This is because Also, when a thin film is produced,
It is preferable to use a solvent having a high boiling point of not lower than 0 ° C. because a uniform initial state can be created. On the other hand, when manufacturing 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 for forming a pattern, it is preferable to apply a uniform solution of the micro pattern forming material by a spin coating method or a dip coating method. This is because it is possible to prevent the history of film formation from remaining by forming a film from a uniform solution. If the coating solution is not uniform due to the formation of micelles with a relatively large particle size in the solution, an inappropriate phase-separated structure may be mixed, making it difficult to form a regular pattern or forming a regular pattern. It is not preferable because it takes time to do.

At the interface between the 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 is as follows via the solubility parameter δ.

[0042]

[Equation 5]

[0043]

[Equation 6]

In the above equation, γ is the surface tension, V is the molar volume of the component, and ΔE ^V is the excess surface free energy. The reason why the surface energy of the polymer is particularly high is that the increase amount of energy ΔE ^V when the polymer chain in the bulk is released into the vacuum is large. That is, the higher this energy is, the higher the tendency to round inward in order to reduce the surface area and the higher the surface energy. Therefore, when two different polymer chains are in contact, it is considered that the polymer chain with higher surface energy tends to be more rounded.

For this reason, the phase diagram is biased toward the polymer phase side having a large surface energy, that is, a large solubility parameter value. This indicates that the composition forming a domain structure such as a lamella, a cylinder, and a sea-island structure is slightly offset depending on the combination of two types of polymer chains. Specifically, when the solubility parameters of the two polymers constituting the blended polymer differ by 1 cal ^0.5 / cm ^1.5 , the optimum composition shifts to the larger of the about 5% solubility parameters.

The thickness of the interface between the phases of the polymer is also an important factor. The interface between the two kinds of polymer chains is not clearly divided into A phase and B phase with an extremely thin surface as a boundary, and 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 kinds of polymers is L, the free energy ΔF of Hemholtz in a heterogeneous system in which the concentration change follows a Gaussian distribution is given by the following formula.

[0047]

[Equation 7]

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

[0049]

[Equation 8]

Here, when z is taken to be 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 difference in surface energy upon contact with the substrate is segregated on the substrate side. For example,
Polystyrene-polymethylmethacrylate (PS-PM
In the (MA) -based blend polymer, PMMA is deposited closer to the substrate. On the contrary, in the polystyrene-polybutadiene (PS-PB) blend polymer, PS is deposited on the substrate side.

In this case, the optimum composition ratio of the blended polymer cannot be unconditionally determined due to the interaction with the substrate,
It can be predicted 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 present on the surface of the substrate is large, so that the composition of the minority phase needs to be larger. For example, in the PS-PMMA system,
Under the same conditions, the composition of PMMA forming islands needs to be higher than the composition of PS forming islands because PMMA easily precipitates on the substrate surface. However, at this time, due to the difference in surface tension, the optimum composition of spheres is unlikely to have the same tendency. The distribution of the size of the structure differs due to the difference in the surface tension between the two types of polymers, and the interaction with the substrate does not make the optimum composition ratio of the two types of polymers rich when they are rich.
For example, the optimum composition of A polymer having affinity for the substrate and A polymer forming dots on the substrate is A: B =
It is assumed to be 20:80. However, when the B polymer forms dots, A: B = 85: 15. This is because when the polymer is adsorbed on the surface of the substrate in a dot shape, an extra volume is required.

In order to form a phase-separated structure in 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%, 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, the number 1
In the case of a thin film having a thickness of about 0 nm, the influence of the interface is significant, so the above optimum value is reduced by about 2 to 5%. If this value is exceeded, a different structure will be created instead of a sea island. In order to adjust the volume fraction, the polymer mixing ratio may be controlled or the molecular volume of the polymer chain may be controlled. Various methods are conceivable for controlling the molecular volume of the polymer chain. For example, when the polyvinyl pyridine chain is quaternized with an alkyl group, the molecular volume of the alkyl group or the counter anion may be changed. Further, a substance having a 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 chain and the B polymer chain are incompatible with each other. In order to form a good phase-separated 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 the micropattern forming method using the same will be described in more detail.

The micropatterning material of the present invention is phase-separated through a nucleation and growth process of a combination of two or more polymers having different properties and capable of selectively removing at least one polymer by some method. It consists of a polymer blend mixed to obtain the composition obtained. Then, the polymer blend is phase-separated and, if necessary, a treatment for changing the state or properties of at least one polymer is performed, and then at least one polymer is selectively removed to obtain a desired micropattern. Can be formed. A specific combination of two or more kinds of 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 using 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 Will be described. These polymers differ from each other in resistance to energy rays. That is, a polymer having hydrogen bonded to the α-position does not break its main chain even when irradiated with energy rays, whereas a polymer having an alkyl group or a halogen bonded to the α-position cuts its main chain when irradiated with energy rays. . The polymer whose main chain has been cut can be selectively removed by wet etching, volatilization by heat treatment, or dry etching.

Therefore, a thin film of the above-mentioned polymer blend is formed on the underlayer, a phase separation structure fixed in 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 cleaved, the polymer phase in which the main chain is cleaved is selectively removed, and the underlayer is processed by using the remaining polymer phase as a mask to transfer the micropattern.

As the energy rays, β rays (electron rays),
Examples include X-rays, γ-rays, and heavy particle beams. Among these, β rays, X rays, and γ rays are excellent because they have excellent permeability into the inside of the polymer thin film and a low cost process is possible. In particular, β rays and X rays are preferable, and β rays having high decomposition efficiency by irradiation are most preferable. As the β-ray (electron beam) source, for example, various electron beam accelerators such as Cockloft-Walton type, Van de Graft type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, high frequency type, etc. should be used. You can

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

On the other hand, the resistance to energy rays is high,
Examples of the polymer whose main chain does not decompose even when irradiated with energy rays include those having hydrogen at the α-position of the monomer unit such as polyethylene, polypropylene, polystyrene, polyacrylic acid, polymethyl acrylate, polyacrylamide and polymethyl vinyl ketone. To be In addition,
It is further preferable that these polymers are crosslinked 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 such as solvent washing or volatilization by heat treatment. Therefore, a fine particle having a phase-separated structure is retained without a dry etching step. Patterns and structures can be formed. This is a great advantage because depending on the electronic material, the dry etching process cannot be used, or even if it can be used, the wet etching is preferable from the viewpoint of cost.

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

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

Incidentally, for example, JP-A No. 11-80414 describes a method of producing a porous material by irradiating ultraviolet rays to decompose polymer chains. However, since ultraviolet rays have poor permeability to organic substances, they are not suitable for making a molded article having a certain thickness porous. Further, when ultraviolet rays are used, it is often difficult to cleave the main chain of only one phase polymer of the two phase polymers because the selectivity of the decomposition reaction of the polymer main chain is low.

On the other hand, β-rays, X-rays, γ-rays, etc. penetrate deeper into the object to be irradiated, have high selectivity for the decomposition reaction of the polymer main chain, have high decomposition efficiency, and are low in cost. Very good. Particularly preferred is β-ray (electron beam) which can be easily irradiated at low cost. The β-ray irradiation amount is not particularly limited, but 100 Gy to 10 MGy, more preferably 1 KGy to 1 MGy, and most preferably 10 KG.
It is set to y-100 KGy. If the irradiation dose is too low, the degradable polymer cannot be fully decomposed.On the other hand, if the irradiation dose is too high, the decomposed product of the degradable polymer may be cured by three-dimensional crosslinking, or even hard-to-decompose polymers. May decompose.

The accelerating voltage varies depending on the thickness of the molded body, that is, the penetration length of β rays into the molded body, but is 10 nm to several tens μ
If it is a thin film of about m, about 20 kV to 2 MV, 100 μ
500 kV for films over m and bulk molded products
It is preferably set to about 10 MV. When the molded product contains a metal molded product, the acceleration voltage may be further increased.

(B) The N / (Nc-No) ratio of the monomer units constituting the polymer is 1.4 or more (however, N
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). The case of using a polymer blend containing two or more polymers will be described. Since these polymers differ from each other in dry etching resistance, one phase polymer can be selectively removed by dry etching.

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

The above parameter N / (Nc-No) will be described in more detail below. 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 showing the dry etching resistance of the polymer, and the larger this value is, the higher the etching rate by dry etching is (the lower the dry etching resistance is). That is, the etching rate V
_{Between the etch} and the above parameters, V _etch ∝N / (Nc
-No). This tendency is due to Ar, O ₂ ,
It hardly depends on the kinds of various etching gases such as CF ₄ and H ₂ (J. Electrochem. Soc., 130, 143 (1983)).
As the etching gas, in addition to Ar, O ₂ , CF ₄ , and H ₂ described in the above documents, 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 nothing to do with etching of inorganic substances such as silicon, glass, and metals.

When concrete parameter values are calculated,
As shown in the chemical formula, polystyrene (PS) monomer unit
Knit is C₈H₈Therefore, 16 / (8-0) = 2.
The polyisoprene (PI) monomer unit is C_Five
H₈Therefore, 13 / (5-0) = 2.6, and
The monomer unit of methyl methacrylate (PMMA) is
C _FiveO₂H₈Therefore, 15 / (5-2) = 5. Shi
Therefore, in the PS-PMMA blend polymer, P
High etching resistance of S, only PMMA is etched
It can be expected to be vulnerable. For example, CF_FourTraveling wave at
150 W, reflected wave 30 W, flow rate 30 sccm, pressure 0.
Reactive ion etching under the condition of 01 torr
(RIE), PMMA is 4 ± 0.
It has been confirmed that the etching rate is about 3 times higher.
It

[0073]

[Chemical 1]

FIG. 3 shows N / (Nc-N of various polymers.
The relationship between the o) value and the dry etching rate is shown. The abbreviations used in FIG. 3 indicate the following polymers, respectively. S
EL-N = (Somer Industries, trade name), PMMA = polymethylmethacrylate, COP = glycidyl methacrylate-ethyl acrylate copolymer, CP-3 = methacrylate-t-butyl methacrylate copolymer, PB
= Polybenzylmethacrylate, FBM = polyhexafluorobutylmethacrylate, FPM = polyfluoropropylmethacrylate, PMIPK = polymethylisopropenylketone, PS = polystyrene, CMS = chloromethylated polystyrene, PαMS = polyα-methylstyrene, PVN = polyvinyl Naphthalene, PVB = polyvinylbiphenyl, CPB = cyclized polybutadiene.
As shown in this figure, V _etch ∝N / (Nc-No)
It turns out that the relationship is established.

Generally, when an aromatic ring is contained, the carbon content is relatively high because it contains a double bond, so that the values of the above parameters are small. As can be seen from the above parameters, the more carbon in the polymer (the smaller the parameter value), the better the dry etching resistance, and the more oxygen (the larger the parameter value) the lower the dry etching resistance. This can be qualitatively explained as follows. Carbon has low reactivity to radicals and is chemically stable. Therefore, if the polymer contains a large amount of carbon, it is difficult for the radicals to react even when attacked by various radicals, and the etching resistance is improved. On the other hand, since oxygen has a high reactivity with radicals, if the oxygen content in the polymer is high, the etching rate is high and the etching resistance is low. Further, if oxygen is contained in the polymer, oxygen radicals are easily generated. Therefore, when a fluorine-based etching gas such as CF ₄ is used, F radicals are multiplied by the action of oxygen radicals to increase radicals involved in etching. 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 becomes large and it is easily etched.

As described above, the N / N ratio of the A polymer and the B polymer constituting the micropatterning material of the present invention is
If the ratio of (Nc-No) parameters is 1.4 or more,
A clear pattern is formed by etching. When this ratio is 1.5 or more, and more preferably 2 or more, the two polymers have a large difference in etching rate, and thus the stability during processing is improved. Further, the etching selection ratio of the two polymers when actually dry-etched is 1.3 or more,
Further, it is preferably 2 or more, more preferably 3 or more.

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

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

Therefore, after forming a thin film of the above-mentioned polymer blend on the underlayer and forming a phase-separated structure fixed in the nucleation and growth process in the thin film, the thin film is heated to 120 ° C. or higher and at least one kind of film is formed. It is possible to transfer the micropattern by selectively thermally decomposing and removing the polymer phase and processing the underlayer using the remaining polymer phase as a mask.

The difference in the thermal decomposition temperature between the heat resistant polymer and the thermally decomposable polymer (the temperature at which the weight is halved 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, the most preferable temperature is 100 ° C. or higher. Further, it is more preferable that the heat resistant polymer is one that three-dimensionally crosslinks at a temperature not lower than the thermal decomposition initiation 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 polyacrylic acid ester and polymethacrylic acid ester, 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, it is also possible to use a polymer having a side chain or a main chain which is crosslinked by heat to form a heat-resistant molecular structure. For example, POSS (Polyhedral Oligomeric Silsesquio) is attached to the side chain or the main chain.
A polymer having siloxane clusters such as xane: polysiloxane T ₈ cube) may be used. For example, those obtained by polymerizing a methacrylate T ₈ cube represented by the following chemical formula are preferable.

[0084]

[Chemical 2]

(R represents H or a substituted or unsubstituted alkyl group, aryl group or aralkyl group, and examples thereof include a methyl group, an ethyl group, a butyl group, an isopropyl group and a phenyl group).

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

[0087]

[Chemical 3]

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

The polysilane may be a homopolymer or a copolymer, and may have a structure in which two or more kinds of polysilane are bonded to each other through 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 polymer which is alkali-soluble (including a polymer which can be changed from alkali-insoluble to alkali-soluble by some treatment) and at least one polymer which is alkali-insoluble. thing. When the polymer blend containing these polymers is treated with an alkali developing solution, the alkali-soluble polymer can be selectively removed.

Therefore, after forming a thin film of the above-mentioned polymer blend on the substrate and forming a phase-separated structure immobilized in the nucleation and growth process in the thin film, the thin film is developed with an alkali developing solution to obtain an alkali-soluble polymer. The micropattern can be transferred by selectively removing the phase (3) and processing the underlayer using the remaining polymer phase as a mask.

Examples of the alkali-soluble polymer include novolak resins such as phenol novolac and naphthol novolac, main chain alicyclic polymers such as polyisobornene, polynorbornene, polycyclohexene, polycyclopentene and polycyclooctene, and hydroxyl groups, carboxyl groups, carbonyl groups, etc. Introduced a substituent of, polyhydroxystyrene, phenol resin such as polyhydroxyvinylnaphthalene, polymethacrylic acid or polyacrylic acid and those in which these α-positions are substituted with halogen,
Examples thereof include polyvinyl alcohol, polyvinyl acetate, maleic anhydride and the like.

Typical examples of the alkali-insoluble polymer include aromatic polymers such as polystyrene, rubber-based polymers such as polybutadiene and polyisoprene, and acrylic polymers such as polymethylmethacrylate. Most of the polymers are soluble in alkali. Since it is not present, many can be used as the alkali-insoluble polymer.

It is also possible to introduce an alkali dissolution inhibiting group into the alkali-soluble polymer to give an alkali-insoluble resin. Examples of the compound used for introducing the 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-butoxycarbonate and methoxy. Alkoxy carbonates such as carbonate and ethoxy carbonate; silyl ethers such as trimethylsilyl ether, triethylsilyl ether, 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, dimethylthexylsilyl 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, cycloheptyl denketal; 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 trimethylsilyl ketene acetal, triethylsilyl ketene acetal, t-butyldimethylsilyl ketene acetal; di-t- Butyl silyl ether, 1,3-
Silyl ethers such as 1 ', 1', 3 ', 3'-tetraisopropyldicycloxanilidene ether, 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-dioxolane, 4-bromomethyl-1,3-dioxolane, 4,3′-butenyl-1,3
-Dioxolane, 4,5-dimethoxymethyl-1,3
-Cyclic acetals and ketals such as dioxolane; O-trimethylsilyl cyanohydrin,
Examples thereof include cyanohydrins such as O-1-ethoxyethyl cyanohydrin and O-tetrahydropyranyl cyanohydrin.

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

In this case, when a photo-acid generator which reacts with 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 can be improved by exposure. Can be controlled.
As the photo-acid generator, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalene sulfonate, diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzene sulfonate, 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) thioranium triflate, cyclohexylmethyl (2- Oxocyclohexyl) sulfonium triflate, dicyclohexyl (2-oxocyclohexyl) sulfonium triflate, dimethyl (2-oxocyclohexyl) sulfonium triflate, S- (trifluoromethyl) dibenzothiophenium trifluoromethanesulfonic acid, Se-
(Trifluoromethyl) dibenzothiophenium trifluoromethanesulfonic acid, iodonium salts such as I-dibenzothiophenium trifluoromethanesulfonic acid,
Onium salts such as sulfonium salts, phosphonium salts, diazonium salts and pyridinium salts, 1,2-naphthoquinonediazide-4-sulfonyl chlorides, 2,3,4,4-
1,3-such as 1,2-naphthoquinonediazide-4-sulfonic acid ester of tetrahydrobenzophenone and 1,2-naphthoquinonediazide-4-sulfonic acid ester of 1,1,1-tris (4-hydroxyphenyl) ethane
Diazoketone compounds such as diketo-2-diazo compounds, diazobenzoquinone compounds, 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 Examples thereof include phenacyl sulfone, mesityl phenacyl sulfone, β-keto sulfone such as bis (phenylsulfonyl) methane, and sulfone compounds such as β-sulfonyl sulfone.

As the alkaline solution used as the developing solution, for example, an inorganic alkaline aqueous solution such as an aqueous solution of sodium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, etc., a tetramethylammonium hydroxide aqueous solution, Organic alkali aqueous solution such as trimethylhydroxyethylammonium hydroxide aqueous solution, ethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, pyrrole, piperidine, choline and the like, alcohols, interfaces The thing which added the activator is mentioned. After the development treatment, the substrate and the polymer film are rinsed with 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 kinds of mutually incompatible polymers are dissolved in a suitable solvent to prepare a coating solution. A multi-component multi-phase polymer thin film is formed by applying this coating solution on a substrate and drying it. 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 molded into a desired shape by a hot pressing method, an injection molding method, a transfer molding method, or the like. After film formation or molding, a better phase-separated structure can be formed by annealing at a temperature not lower than the glass transition point of the polymer material.

In the coating film formation process, an additive such as a dopant may be mixed with the coating solution. As such an additive, it is preferable to use one having a high specific affinity with one of the polymers that are phase-separated from each other. In this case, when the phase-separated structure is formed, the dopant can be easily unevenly distributed only in the phase having good affinity.

Examples of additives include Cr, V, Nb,
Ti, Al, Mo, Li, Lu, Rh, Pb, Pt, A
A metal element such as u may be used. These metallic elements are
It can be used as a growth nucleus of a magnetic film of a magnetic recording medium or as an electrode material for batteries. You may use the additive which produces | generates the above metal elements by reduction. Examples of 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-octanedionate, 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 salts and the like can be mentioned.

The metal added as an additive may be an ion, or may be ultrafine particles of several nm to several tens of nm whose affinity to one phase is specifically enhanced by surface treatment. For example, the metal fine particles whose surface is coated with the A polymer are segregated in the A polymer phase, and the metal fine particles whose surface is coated with the B polymer are segregated in the B polymer phase. In this case, the surface-treated metal fine particles are deposited in the substantially central portion of the phase showing 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 are deposited at the interface between the A polymer phase and the B polymer phase. By using such a method, even the same metal element can be intentionally deposited in different phases. Even when such ultrafine particles are added to the coating solution, the ultrafine particles can be localized only in the phase having a good affinity by the same coating operation as described above.

The additives may be chemically bonded to the side chains or backbone of the polymer, rather than simply mixed. In this case, the additive can be easily localized in the specific phase by modifying only the polymer forming the specific phase with the functional molecular structure. In addition, by introducing a structure into the main chain or side chain of the polymer that easily binds to a specific additive and contacting with the vapor or solution of the additive before or after forming the phase-separated structure, the additive is introduced into the polymer. You may. For example, if a chelate structure is introduced into the polymer, a metal ion or the like can be added. The chelate structure may be introduced into the main chain or may be introduced as a substituent at the ester site of the polyacrylic acid ester. If a structure having ion exchange ability such as a pyridinium salt structure is introduced into the polymer, a metal ion or the like can be added by counter ion 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 addition amount of the plasticizer is not particularly limited, but it 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 added is too small, the effect of accelerating the formation of the phase separation structure cannot be sufficiently obtained, and if it is too large, the regularity of the phase separation structure tends to be disturbed.

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

As described above, when the blended polymer is phase-separated in the present invention, it is preferable to anneal at a glass transition temperature or higher. However, when this heat treatment is performed in an atmosphere containing oxygen or the like, the polymer is modified and deteriorated due to an oxidation reaction and the like, a good microphase-separated structure cannot be formed, the heat treatment time becomes long, and Etching selectivity may not be obtained. In order to prevent such deterioration of the polymer, it is preferable to perform the heat treatment under oxygen-free conditions, preferably in a dark place where photo-degradation does not easily occur. However, annealing under oxygen-free conditions requires strict atmosphere control, and therefore tends to increase manufacturing costs.

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

Specifically, for example, 3,5-di-tert-
Phenol-based antioxidants such as butyl-4-hydroxytoluene, phosphorus-based antioxidants, sulfur-based antioxidants such as sulfide derivatives, bis (2,2,6,6-tetramethylpiperidinyl-4) sebacate, etc. HALS (Hindered Amine Light Stab)
ilizer) -based photodegradation inhibitor, metal complex-based photodegradation inhibitor such as copper or nickel, etc. are used.

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

The polymer may be three-dimensionally cross-linked with each other after the phase separation structure is formed by adding a cross-linking agent or introducing a cross-linkable group to the polymer. By such cross-linking, the thermal or mechanical strength of the phase-separated structure can be further improved and the stability can be improved. In consideration of durability such as heat resistance, it is originally preferable that each phase is incompatible, but even if it is a phase-separated structure composed of incompatible phases, a polymer that forms a phase The durability can be improved by cross-linking each other.

In the present invention, a pattern transfer technique is used to transfer a pattern formed from a micropattern forming material composed of a polymer blend in which two or more kinds of polymers having a dry etching rate ratio of 1.3 or more are transferred onto a substrate. , It is also possible to obtain a pattern with a high aspect ratio. The method of the present invention is a very effective technique because the precision of the position of the pattern is not required so much in a recording medium or a display.

The pattern transfer is realized by combining the following layers. 1. Pattern-forming film As the pattern-forming film, a polymer that mixes two or more kinds of polymers having a dry etching rate ratio of 1.3 or more, which self-develops a phase separation structure of nanometer to micron order as described above. Use a blend.

2. Pattern transfer film The pattern transfer film is a layer provided below the pattern forming film and to which the pattern formed on the pattern forming film is transferred. After the phase of the polymer of the pattern forming film, which has a low etching resistance, is etched, the pattern transfer film is subsequently etched. It is desirable to set the thickness and etching rate of the pattern transfer film so that the etching is completed before the phase having high etching resistance of 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, and more preferably, as compared with a polymer having a slow dry etching rate among the blended polymers forming the pattern forming film. It is preferably 2 or more. As the pattern transfer film, A
u, Al, Cr or other metal thin film, polysilane, N / (N
An organic substance having a value of c-No) larger than 3 and easily etched is desirable.

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

[0115]

[Chemical 4]

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

Specific examples of the polysilane include poly (methylphenylsilane), poly (diphenylsilane), poly (methylchloromethylphenylsilane) and the like. Further, the polysilane may be a homopolymer or a copolymer, and may have a structure in which two or more kinds of polysilane are bonded to each other through 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 polysilane is not particularly limited, but Mw
= 2000-1,000,000, and Mw = 3000-
The range of 100,000 is preferable. If the molecular weight is too small, the coating property and etching resistance of the polysilane film deteriorate. Further, there is a possibility that the pattern forming film is redissolved when applied and mixing occurs between the pattern forming film and the polysilane film which is the pattern transfer film. On the other hand, if the molecular weight is too high, the solubility of 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-mentioned antioxidant or photodegradation inhibitor similar to the one added to the micropattern forming material. The addition amount of these additives is not particularly limited, but 0.01 to 10 w
t%, and more preferably 0.05 to 2 wt%. If the amount added is too small, the effect of addition cannot be obtained, and if the amount added is too large, the etching characteristics of the polysilane may deteriorate.

3. Lower Layer Pattern Transfer Film The lower layer pattern transfer film does not necessarily have to be provided, but if it is used, a pattern having a high aspect ratio can be formed. If the upper pattern transfer film was formed, and more at refractory metal thin film is etched by O _2, when etching with O ₂ an upper pattern transfer film as a mask, it is possible to form a very deep holes in the lower 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. The material of the lower layer pattern transfer film is preferably one having a dry etching resistance to a fluorocarbon gas such as CF ₄ . Specifically, derivatives such as polystyrene and polyhydroxystyrene, polyvinyl naphthalene and its derivatives, and polymers such as novolac resins are used. Since these polymers do not need to have the same molecular weight, a relatively inexpensive resin that can be industrially easily produced by a radical polymerization method or the like can be selected, and it is advantageous in terms of cost.

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

First, the above-mentioned polymer is formed as a lower layer pattern transfer film on the substrate by a spin coating method or a dipping method. It is desirable that the thickness of the lower layer pattern transfer film be equal to or greater than the depth of the holes to be transferred. A film of an inorganic material such as metal or SiO is formed as an upper layer pattern transfer film on the lower layer pattern transfer film by a vacuum deposition method or a plating method. The thickness of the upper layer pattern transfer film is preferably thinner than that 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. Its thickness is preferably about the same as the size of the structure to be formed.

The dry etching rate of the upper pattern transfer film is preferably higher than that of the pattern forming film. Specifically, it is preferable that the upper layer pattern transfer film is etched at a rate of at least about 1.3 times, and more than twice as much as that of the pattern forming film. However, when the polymer film is provided as the lower layer pattern transfer film under the upper layer pattern transfer film, the above 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 pattern transfer film has resistance to etching by oxygen, the lower 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 of that of the pattern forming film.

After forming each film as described above, annealing is carried out if necessary to form a micro phase separation structure in the pattern forming film. Then, by performing RIE with a fluorocarbon gas, at least one phase of the phase-separated structure formed in the film is selectively removed to leave the other phases. The upper pattern transfer film (eg, metal) is also etched to transfer a phase-separated structure, eg, 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 layer pattern transfer film made of metal is not etched and only the lower layer pattern transfer film made of organic polymer is etched, so that a structure having a very high aspect ratio can be formed. At the same time, the pattern forming film is also ashed. Using the remaining lower layer pattern transfer film as a mask, RIE is performed again with a fluorocarbon gas to etch the substrate. As a result, holes having a very high aspect ratio can be formed on the base substrate on the order of nanometers to microns.

Instead of the above method, the pattern forming film is irradiated with β-rays to break the polymer main chain of at least one phase, and then the phase in which the polymer main chain is cut is selectively removed by wet etching. The method of doing is also effective. After this step, by performing the same steps as described above, a pattern of nanometer to micron order can be formed on the substrate. In the above process, RIE
Wet etching may be used instead of the process. However, the pattern shape is likely to collapse during pattern transfer.

[0125]

EXAMPLES The present invention will be specifically described below based on examples. However, the present invention is not limited to these examples.

Example 1 Low molecular weight polystyrene (P
S) (Mw = 2500) and polymethylmethacrylate (PMMA) (Mw = 5000) were mixed at a weight ratio of 80:20, and the whole was made into a 10 wt% ethyl cellosolve acetate solution. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm. After vaporizing the solvent at 110 ° C. for 90 seconds, annealing was performed at 210 ° C. for 10 minutes in a nitrogen atmosphere using an oven, and subsequently at 135 ° C. for 10 hours. These annealing temperatures are set higher than the glass transition temperatures of PS and PMMA.
210 ℃ is the temperature just before the decomposition of PMMA,
The short-time annealing at 210 ° C. flattens the film, and the history after spin coating can be erased. Also,
When annealing is performed at a temperature of about 135 ° C., the phase separation proceeds efficiently and a phase separated structure is formed. Observation in phase mode with an atomic force microscope revealed a diameter of 1 μm in the PS sea.
The structure in which the islands of PMMA are scattered to some extent was confirmed.

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

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
A phase separation film was formed in the same manner as above except that the temperature was 1 hour, and RIE was performed under the same conditions as above. as a result,
A hole pattern similar to the above could be formed on the entire surface of the substrate.
Thus, the annealing time could be significantly shortened by adding the plasticizer to the blend polymer.

[Embodiment 2] In the same manner as in Embodiment 1, 3
A phase-separated film of a blended polymer was formed on an inch diameter SiO substrate. An acceleration voltage of 50 kV and 10
Irradiate the entire surface with an electron beam at a dose of 0 μC / cm ² ,
The main chain of MMA was cleaved. The phase-separated film was developed for 60 seconds with a developing solution for electron beam resist (MIB: IPA 3: 7 mixed solution), and then rinsed with IPA to remove PMMA whose main chain was cleaved by the electron beam. Next, the substrate was etched with hydrofluoric acid for 1 minute using the remaining pattern containing PS as a main component as a mask. After that, 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.

Further, instead of irradiating with an electron beam, X-rays with a wavelength of 0.154 nm were irradiated at a dose of 1 J / cm ² , and pattern formation was performed in the same manner as described above. 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.

Example 3 PS and PM used in Example 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 by the same method as in Example 1. This phase separation film is irradiated with β-rays to P
The main chain of MMA was cleaved. The phase-separated film was developed with a developing solution for electron beam resist, and the main chain was cleaved by β rays.
The MMA was removed. Next, the magnetic film was etched with hydrochloric acid for 1 minute using the remaining pattern containing PS as a main component as a mask. After that, ultrasonic cleaning was performed in acetone to remove the remaining mask. As a result, protruding magnetic films having a diameter of 1 μm and a height of 100 nm were formed on the entire surface of the substrate at substantially equal intervals. By using this method, the magnetic film can be directly processed by a wet method and left in the form of islands.

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

For this sample, CF ₄ , 0.01 to
RIE was performed under the conditions of rr, traveling wave 150 W, and reflected wave 30 W to selectively etch only the PMMA portion of the phase separation film, and the remaining PS was used as a mask to etch the aluminum film. Then, for this sample,
₂ , 0.01 torr, traveling wave 150W, reflected wave 30W
The ashing was performed under the conditions described above to remove the remaining mask made of PS and the polystyrene film exposed at the portion where the aluminum film was etched. Again for this sample, CF ₄ , 0.01 torr, traveling wave 150 W,
RIE was performed under the condition of a reflected wave of 30 W to etch the aluminum film as the upper layer pattern transfer film and the exposed quartz substrate. Again for 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, the average diameter of 1 μm was observed on the entire surface of the quartz substrate.
A hole having a very high aspect ratio of m and a depth of 5 μm was formed.

Example 5 Low molecular weight polystyrene (P
S) (Mw = 2500) and polyhydroxystyrene (P
HS) (Mw = 5000) was mixed at a weight ratio of 80:20, and the whole was made into a 10 wt% propylene glycol monoethyl ether acetate (PGMEA) solution. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm. After vaporizing the solvent at 110 ° C. for 90 seconds, use an oven at 210 ° C. for 1 hour in a nitrogen atmosphere.
Annealing was performed for 0 minutes and subsequently at 160 ° C. for 10 hours.
Observation with a phase mode of an atomic force microscope confirmed a structure in which PHS islands with a diameter of about 1 μm were scattered in the PS sea.

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

For this sample, 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 underlayer was etched by using the above pattern as a mask. Then, with respect to this sample, O ₂ , 0.01 torr
Ashing was performed under the conditions of r, 150 W of traveling wave, and 30 W of reflected wave to remove organic substances (mask made of PS). As a result, holes having a diameter of about 1 μm were formed on the entire surface of the 3-inch SiO substrate at substantially equal intervals.

Even when the substrate having the PS pattern formed thereon was etched with a 1% hydrofluoric acid aqueous solution using the PS pattern as a mask, holes having a diameter of about 1 μm were formed on the entire surface of the substrate at substantially equal intervals. 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
It was made into a 0 wt% cyclohexanone solution. This solution was spin-coated on a 3-inch diameter SiO substrate at 2500 rpm. After vaporizing 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 in an oven at 150 ° C. for 1 hour. As a result, it was confirmed that the PEO portion was decomposed and the polystyrene portion had holes. The polystyrene was softened by heating above the glass transition temperature, but the morphology of the holes was preserved.

For this sample, 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 underlayer was etched by using the above pattern as a mask. Then, with respect to this sample, O ₂ , 0.01 torr
Ashing was performed under the conditions of r, 150 W of traveling wave, and 30 W of reflected wave to remove organic substances (mask made of PS). As a result, holes having a diameter of about 1 μm were formed on the entire surface of the 3-inch SiO substrate at substantially equal intervals.

Example 7 Polystyrene (PS) (Mw
= 6000) and polytertiary butyl methacrylate (PtBMA) (Mw = 4800) in a weight ratio of 72:28.
The resulting mixture was mixed with 1, and triphenylsulfonium triflate was added to the polymer in an amount of 1% by weight so that the whole solution became 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 vaporized at 110 ° C. for 90 seconds.

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

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

This sample was treated with an alkaline developer (tetramethylammonium hydroxide: 2.38 wt% of TMAH).
It was developed with an aqueous solution) for 60 seconds. As a result, the PMA portion soluble in the alkaline developer was selectively removed. In addition,
A phase separation pattern was visible in the unexposed area, but it was not dissolved in the alkaline developer.

For this sample, 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 underlayer was etched by using the above pattern as a mask. Then, with respect to this sample, O ₂ , 0.01 torr
Ashing was performed under the conditions of r, 150 W of traveling wave, and 30 W of reflected wave to remove organic substances (mask made of PS). As a result, holes having a diameter of about 0.7 μm were formed at substantially equal intervals only on the exposed portion on the 3-inch SiO substrate.

Even when the substrate having a PS pattern formed thereon was etched with a 1% hydrofluoric acid solution using the PS pattern as a mask, a hole having a diameter of about 1 μm was formed only in the exposed portion on the substrate. It was possible to form them at substantially equal intervals.

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

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

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

Next, at the intersection of the gate wiring and the emitter wiring, a resist (OFPR800, 100c manufactured by Tokyo Ohka Co., Ltd.)
p) Protect by patterning. Subsequently, according to the method of Example 5, a solution of the blend polymer is spin-coated on the gate conductor 105, dried, and then annealed to form a polymer phase separation film. RIE is performed on this polymer phase separation film using CF ₄ gas to selectively etch only the PMMA portion of the phase separation film, and the gate conductor 105 is etched using the remaining PS pattern as a mask. Transfer the pattern. afterwards,
Ashing is performed with an O ₂ asher to remove the 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 or CH using buffered hydrofluoric acid (BHF)
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, an exfoliation layer is formed by obliquely evaporating aluminum using an electron beam (EB) evaporation method. By the EB vapor deposition method, molybdenum is vertically vapor-deposited on the peeling layer in the vertical direction, and molybdenum is deposited in the opening 106 in a cone shape to form the emitter 107. After that, the peeling layer is removed with a peeling solution such as phosphoric acid to manufacture an FED element as shown in FIG.

[Embodiment 9] An example of manufacturing the FED element shown in FIG. 5 will be described. Diagonal 14 inches, thickness 5mm
Pyrex glass substrate 201 of No. 1 was cleaned, and its surface was roughened by plasma treatment. This glass substrate 20
Emitter wiring 2 with a width of 350 μm parallel to the long side direction of 1
02 was manufactured at a pitch of 450 μm. At this time, the substrate 20
Regions of 2 inches each from both sides parallel to the direction of one emitter wiring 202 were used as wiring margins, and patterning was performed so that the emitter wiring 202 was not formed in this area. Specifically, a PVA film was applied, exposed (photopolymerized) by ultraviolet rays through a mask and developed, and patterned so that the PVA film was left in the region between the emitter wirings 202. The patterning accuracy at this time was 15 μm. 50 nm by electroless plating
Of the PVA film and the Ni on it after growing the Ni film of
The membrane was lifted off. Using the remaining Ni film as an electrode, a 1 μm Au film was grown by electrolytic plating.

SiO ₂ film 2 as an insulating layer by LPD method
03 was grown to 1 μm. This SiO ₂ film 203 contained many particle defects, but its density was 1
The number was about 1000 per square cm, which was a level with no practical problem. The film formed on Au was slightly darkened, but the withstand voltage was 100 V per 1 μm, which was at a practically acceptable level. This SiO ₂ film 203
Covered conformally the stepped portion of the Au-Ni wiring, and there was no exposed portion of Au. After a 30 nm Pd film was grown 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 was formed 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 the gate wiring 204 are used as wiring margins.
Patterning was performed so that the gate wiring 204 was not formed in this region. Specifically, PV as in the above
A film was applied, exposed (photopolymerized) by ultraviolet rays through a mask and developed, and patterned so that the PVA film was left on the gate wiring 204, and the remaining exposed region was removed by etching. The patterning accuracy at this time was also 15 μm.

Next, the gate wiring 204 and a part of the SiO ₂ film 203 were removed until the emitter wiring 202 was exposed, and patterning was performed to provide a substantially circular opening 205. There are two reasons for separately patterning the gate wiring 204 and the opening 205.
First, 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
Is not necessarily neatly arranged, and it suffices that the openings 205 having a substantially uniform opening diameter be present in each pixel in an approximately equal number.

Specifically, the opening 205 is formed as follows.
Was patterned. Polystyrene (PS) (M
w = 6000 and polytertiary butyl methacrylate (PtBMA) (Mw = 4800) in a weight ratio of 72:
Mix at 28, add 1.5% by weight of naphthylimide triflate to the polymer, and add 10% by weight to the whole.
It was filtered with an ethyl cellosolve acetate solution. This solution was spin-coated on the gate wiring 204 and dried at 110 ° C. to form a polymer film having a film thickness of 970 nm. Except for the intersection of the gate wiring 204 and the emitter wiring 202, only the region forming the opening 205 was exposed by the g-line to generate an acid from the photo-acid generator. Annealing is performed at 150 ° C. for 1 hour in an oven in a nitrogen atmosphere to form a phase separation film, and at the same time, a poly-
Butyl acrylate was decomposed with acid to polyacrylic acid. As a result of reflow during annealing, the film thickness of the polymer film on the gate wiring 204 was 1 μm. Immerse the entire substrate in an alkaline solution for 3 minutes to remove the "islands" of polyacrylic acid, rinse with pure water,
The gate wiring 204 was exposed. By RIE, the gate wiring 204 was etched, and further the SiO ₂ film 203 thereunder was etched to expose the emitter wiring 202.

Next, a resistance layer 206 was formed in the opening 205 by electrophoresis. This work was performed by dividing the emitter wiring into 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 a fullerene having a particle diameter of 10 nm at a weight ratio of 1000: 1 was used. 0.4 wt% of this mixture was dispersed in a dispersion solvent (ISOPAR L, manufactured by Exxon Chemical). In addition, zirconium naphthenate (manufactured by Dainippon Ink and Chemicals, Inc.) as a metal salt was added to the polyimide / carbon fine particle mixture in an amount of 10 wt.
% Added. The substrate 201 is immersed in the dispersion liquid to form the substrate 20.
Counter electrodes were arranged at intervals 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 applying the voltage, a current of several mA started to flow, but the current exponentially decayed and was not observed after 2 minutes. At this point, all the resistance material dispersed in the dispersion solvent was deposited on the substrate 201. Subsequently, the counter substrate is grounded, and the gate wiring 204 is +
By applying 50 V, fine particles adhering to the gate wiring 204 were migrated in a solvent and removed. Further, the resistance layer 206 was fixed to the emitter wiring 202 by annealing at 300 ° C. in a nitrogen atmosphere.

Then, in the same manner as above, the particle emitter layer 207 was deposited by electrophoresis. Fine particle emitter layer 2
As the material of No. 07, cubic boron nitride fine particles having a particle size of 100 nm (manufactured by Showa Denko, product name SBN-B) were prepared. The BN fine particles were treated with dilute hydrofluoric acid and then treated with hydrogen plasma at 450 ° C. 0.2 wt% of the BN fine particles were dispersed in the same solvent used for forming the resistance layer. In addition, zirconium naphthenate is used in an amount of 10 wt% with respect to BN particles.
Was added. After the BN particles were deposited by the same method as described above, the particles adhering to the gate wiring 204 were removed.
Further, by annealing in a hydrogen atmosphere at 350 ° C., the particle emitter layer 207 was fixed to the resistance layer 206.

A face plate 211 having an anode electrode layer 212 made of ITO and a fluorescent layer 213 formed thereon was attached to the obtained electron-emitting device array via a spacer 208 having a height of 4 mm, and the face plate 211 was placed in a vacuum chamber. 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. The unselected emitter wiring 202 and gate wiring 204 were both set to 0V. The selected emitter wiring 202 and gate wiring 204 are respectively-
Biased to 15V and + 15V. As a result, electron emission occurred and bright spots were confirmed on the fluorescent layer 213. Select multiple pixels across the entire display area of the display,
The brightness was measured under the same conditions. As a result, the variation in brightness was within 3%.

[0158]

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

[Brief description of drawings]

1 is a phase diagram of a blended polymer.

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

FIG. 3 is a diagram showing a relationship between N / (Nc-No) values of various polymers and 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 cross-sectional view of another field emission display manufactured in the example 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 ... Resistance layer 207 ... Fine particle emitter layer 208 ... Spacer 211 ... Face plate 212 ... Anode electrode layer 213 ... Fluorescent layer

Continuation of the front page (56) Reference JP-A-11-80414 (JP, A) JP-A 64-1739 (JP, A) JP-A 5-287084 (JP, A) JP-A-2-279741 (JP , A) JP-A-9-132724 (JP, A) JP-A-9-316428 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (5)

(57) [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. A step of forming a thin film of a micropattern forming material, a step of forming a phase-separated structure in the thin film, and a step of irradiating the thin film with a high energy ray to cut the main chain of at least one polymer, A method for forming a micropattern, comprising: a step of selectively removing a polymer phase whose main chain has been cleaved; and a step of processing an underlayer using the remaining polymer phase as a mask. 2. The N / (Nc-No) ratio of the monomer units constituting the polymer on the substrate is 1.4 or more (where N is the total number of atoms of the monomer unit and Nc is the number of carbon atoms of the monomer unit). , No is the number of oxygen atoms of the monomer unit), a step of forming a thin film of a micropattern forming material comprising a polymer blend containing two or more polymers, and a step of forming a phase-separated structure in the thin film, A method for forming a micropattern, comprising: a step of selectively removing at least one polymer phase by etching a thin film; and a step of processing an underlayer using the remaining polymer phase as a mask. 3. A step of forming a thin film of a micropattern-forming material, which comprises a polymer blend containing two or more kinds of polymers having different thermal decomposition properties at a temperature of 120 ° C. or more, on a substrate, and a phase in the thin film. Forming a separation structure; heating the thin film to 120 ° C. or higher to selectively thermally decompose and remove at least one polymer phase; and processing the underlayer using the remaining polymer phase as a mask. A method of forming a micropattern, comprising the steps of: 4. An alkali-soluble at least 1 layer on the substrate.
A thin film of a micropatterning material comprising a polymer blend containing one polymer and at least one alkali-insoluble polymer, forming a phase separation structure in the thin film, and developing the thin film with an alkali. A method for forming a micropattern, comprising: a step of developing with a liquid to selectively remove an alkali-soluble polymer phase; and a step of processing an underlayer 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-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. A step of transferring the pattern of the phase separation structure to the pattern transfer film, and a step of etching the base using the pattern transfer film having the pattern of the phase separation structure transferred as an etching mask to transfer the pattern of the phase separation structure to the base A method for forming a micropattern, comprising: