JP7283739B2 - Fine Wiring Structure Manufacturing Method and Fine Wiring Structure Manufacturing Apparatus - Google Patents

Description

The present invention relates to a fine wiring structure manufacturing method and a fine wiring structure manufacturing apparatus.

Conventionally, fine wiring in integrated circuits has been formed by ultra-fine processing using extremely expensive extreme ultraviolet (EUV), or by repeating subtractive lithography and etching. There are problems that it is a very complicated process and that it is difficult to deal with finer processing sizes on the order of nanometers. Therefore, in order to solve these problems, a self-organizing material such as a diblock copolymer is used to form a regular periodic structure by heat treatment or the like, and a fine pattern with a nanometer level size of several tens of nm or less is formed. Directed Self-Assembly (DSA) lithography technology has been proposed (see, for example, Non-Patent Document 1).

As a method for forming fine wiring such as through electrodes and bumps using this DSA, the inventors of the present invention use self-organizing metal particles and a polymer, for example, to form a polymer layer inside the guide. Then, a method of forming a metal column inside the polymer layer (see, for example, Patent Document 1), or a mixture of a block copolymer and one polymer of the block copolymer modified with a metal However, a method has been developed in which a nanowire wiring in which modified metals are continuous is formed by self-organizing a block copolymer (see, for example, Non-Patent Document 2).

In addition, since general polymer materials are composed of light elements such as C, H, N, and O, they have good electron beam permeability, and it is possible to obtain sufficient contrast to recognize the internal structure. difficult. Therefore, a staining method has been developed that makes it possible to identify the internal structure of a polymer material by staining and fixing the polymer material with a heavy metal having high electron beam scattering performance (see, for example, Non-Patent Documents 3 and 4).

Naoko Kihara, "Self-Assembly Lithography Technology", Toshiba Review, 2012, Vol.67, No.4, p.44-47 Takafumi Fukushima, Mariappan Murugesan, and Mitsumasa Koyanagi, “DSA Technology with Metal Nanocomposites for Advanced Interconnections”, 4th International Symposium on DSA, November 11-13, 2018, poster Minoru Okamura, "Internal Structural Observation of Polymer Materials", 2002, No. 2002-I (Vol.15), p.12-14 Sang-Min Park, Sang-Hyun Yun, Byeong-Hyeok Sohn, “Variations of the Lamellar Period in Thin Films of Diblock Copolymers by Selective Staining Agents”, Macromol. Chem. Phys., 2002, 203, No.14, p. 2069-2074

International publication WO2016/035625

The method described in Patent Document 1 can form fine wiring such as through electrodes and bumps by a relatively simple method. has become 100 nm or more, and there has been a problem that it is difficult to make finer nanometer-level wiring. In addition, the method described in Non-Patent Document 2 can form nanometer-level fine wiring, but it is said that a process for manufacturing a polymer modified with a metal is required as a pre-process for self-assembly. I had a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and provides a fine wiring structure manufacturing method and a fine wiring structure manufacturing apparatus capable of forming nanometer-level fine wiring with fewer steps. for the purpose.

In order to achieve the above object, a method for manufacturing a fine wiring structure according to the present invention includes disposing a phase-separated body that phase-separates when heat is applied at a desired position, and performing a heat treatment on the phase-separated body to phase-separate. and a diffusion step of diffusing a conductor or an insulator into at least one of the phases separated in the phase separation step.

In the method for manufacturing a fine wiring structure according to the present invention, by diffusing a conductor or an insulator in at least one phase among the phases separated by heat treatment, a phase with which electricity is easily conducted and a phase with which electricity is difficult to conduct can be formed. can. As a result, it is possible to form a fine wiring in which the phase through which electricity is easily conducted is a conductor. Also, since the self-organization of the phase separation is used, nanometer-level fine wiring can be formed. The method for manufacturing a fine wiring structure according to the present invention can form fine wiring such as through electrodes, bumps, and multilayer wiring.

In addition, the method for manufacturing a fine wiring structure according to the present invention uses a relatively simple method as the diffusion process, so that the conventional method in which lithography and etching are repeated, or the manufacturing method in which a polymer is modified with a metal is used. A fine wiring can be formed in a smaller number of steps compared to the method of performing a pre-process. Any relatively simple diffusion process may be used, for example, the dyeing method described in Non-Patent Documents 3 or 4 may be used.

In the method for producing a fine wiring structure according to the present invention, the phase-separated material is preferably composed of two or more types of polymers that phase-separate when heat is applied, and is particularly preferably a block copolymer. The phase separator is, for example, a block copolymer containing polystyrene (PS) and polymethyl methacrylate (PMMA), Poly(styrene-b-4-vinyl pyridine), Poly(styrene-b-2-vinyl pyridine). , Poly(styrene-b-dimethyl siloxane), Poly(styrene-b-hydroxystyrene), Poly(styrene-b-lactic acid), Poly(styrene-b-trimethylsilylstyrene), Poly(styrene-b-butadiene), etc. It is a copolymer.

The method for manufacturing a fine wiring structure according to the present invention may have a removing step of removing a polymer present in the phase in which the conductor or the insulator is diffused in the diffusion step. In this case, the removal step can leave only conductors or insulators. When the conductor is left, the electrical conductivity can be increased and the electrical resistance can be kept low, and when the insulator is left, the electrical conductivity can be decreased and electric leakage can be prevented.

In the method for manufacturing a fine wiring structure according to the present invention, the phase separation step may dispose the solution containing the phase separated body at the desired position. In this case, fine wiring can be easily formed at desired positions. Moreover, in this case, the solution may contain conductive particles. At this time, the phase separation process allows the conductive particles to aggregate into at least one phase, thereby promoting the formation of fine wiring.

In the method for manufacturing a fine wiring structure according to the present invention, the diffusion step dyes the first phase out of the phases separated in the phase separation step using a first staining agent to dye the first phase. the conductor may be diffused into the phase of In this case, the conductor can be diffused relatively easily by dyeing. The first phase and first staining agent may be any combination that allows the diffusion of electrically conductive substances into the first phase when dyed with the first staining agent. For example, the first phase consists of polymers containing -CH=CH-, -CH ₂ -CH ₂ -, -NH ₂ , or -CONH as functional groups, and the first dye is It may be osmium tetroxide ( _OsO4 ), ruthenium tetroxide ( _RuO4 ), or phosphotungstic acid. More specifically, the first phase may be polystyrene (PS) and the first dye may be ruthenium tetroxide ( _RuO4 ), in which case the conductor is a first phase can be diffused with ruthenium dioxide (RuO ₂ ).

Further, in this case, a reduction step may be provided for reducing the conductor diffused into the first phase in the diffusion step. By reducing the conductor in the reduction step, a material with higher electrical conductivity and lower electrical resistance can be obtained. For example, when the conductor diffused into the first phase is ruthenium dioxide (RuO ₂ ), a reduction step can reduce it to pure ruthenium (Ru).

In the method for manufacturing a fine wiring structure according to the present invention, the diffusion step dyes the second phase out of the phases separated in the phase separation step using a second staining agent to dye the second phase. The insulator may be diffused into the phase of In this case, the insulator can be diffused relatively easily by dyeing. The second phase and second stain may be any combination that allows diffusion of the insulator into the second phase when stained with the second stain. Specifically, the second phase may be polymethylmethacrylate (PMMA) and _the second dye may be trimethylaluminum ( _{C6H18Al2 )} , wherein the insulator is , aluminum oxide (Al ₂ O ₃ ) can diffuse into the second phase.

An apparatus for manufacturing a fine wiring structure according to the present invention includes a heating means for heating the phase separated body arranged at a desired position so that the phase separated body that undergoes phase separation when heat is applied, and the heating means and diffusion means for diffusing a conductor or an insulator into at least one of the phases separated by heating the phase-separated body.

The apparatus for manufacturing a fine wiring structure according to the present invention can suitably carry out the method for manufacturing a fine wiring structure according to the present invention. In the apparatus for manufacturing a fine wiring structure according to the present invention, a conductor or an insulator is diffused into at least one of the phases separated by heating the phase-separated body with a heating means, thereby allowing the phase to conduct electricity easily. can form a difficult phase. As a result, it is possible to form a fine wiring in which the phase through which electricity is easily conducted is a conductor. Also, since the self-organization of the phase separation is used, nanometer-level fine wiring can be formed. The fine wiring structure manufacturing apparatus according to the present invention can form fine wiring such as through electrodes, bumps, and multilayer wiring.

In the apparatus for manufacturing a fine wiring structure according to the present invention, the diffusing means exposes the phase-separated body phase-separated by the heating means to vapor of a staining agent to convert at least one phase out of the separated phases. Alternatively, the conductor or the insulator may be configured to diffuse. In this case, the dyeing method can be used to diffuse the conductor or insulator relatively easily.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a fine wiring structure and the manufacturing apparatus of a fine wiring structure which can form a fine wiring of a nanometer level by fewer processes can be provided.

(a) Entire longitudinal section, (b) Region A in (a), (c) (a), showing an induced self-assembled composite formed by the method for manufacturing a fine wiring structure according to an embodiment of the present invention. It is a scanning microscope (SEM) photograph of region B in (d) and region C in (b). (a) C, (b) O, (c) Si, (d) Au, (e) by energy dispersive X-ray analysis (EDX) of the A region of the guided self-assembled composite shown in FIG. ) Elemental mapping of Ru, (f) SEM photograph. (a) SEM photograph when measuring voltage, current, and resistance of the induced self-assembled composite shown in FIG. ) and the voltage-resistance relationship (solid line in the figure). (a) SEM photograph during voltage, current, and resistance measurement of Ru-stained PS phase (Ru stained PS) of the induced self-assembled composite shown in FIG. 1, and (b) voltage-current showing the measurement results. 2 is a graph of the relationship (dashed line in the figure) and the voltage-resistance relationship (solid line in the figure). (a) SEM photograph when measuring voltage, current, and resistance between PMMA phase (insulator) and PS phase of the induction self-assembled composite shown in FIG. 1, (b) voltage-current relationship showing the measurement results ( Fig. 2 is a graph of the voltage-resistance relationship (solid line in the figure).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on examples and the like.
A method of manufacturing a fine wiring structure according to an embodiment of the present invention includes a phase separation step and a diffusion step. In the phase separation step, a phase-separated body that undergoes phase separation when heat is applied is arranged at a desired position, and the phase-separated body is subjected to heat treatment to cause phase separation. The phase-separated body preferably consists of two or more types of polymers that phase-separate when heat is applied, such as a block copolymer. Also, in the phase separation step, the solution containing the phase separated bodies may be placed in, for example, a hole or groove-shaped guide. The solution at this time may contain conductive particles.

The diffusion step diffuses the conductor or insulator into at least one of the phases separated in the phase separation step. In the diffusion step, for example, the first phase among the phases separated in the phase separation step may be dyed with a first staining agent to diffuse the conductor into the first phase, and further, The insulator may be diffused into the second phase by dyeing the second phase among the phases separated in the phase separation step with a second dye. For example, when the first phase is a polymer containing -CH=CH- as a functional group, the first dye is osmium tetroxide (OsO ₄ ) and the first phase is -CH ₂ - When the polymer contains CH ₂ —, the first dye is ruthenium tetroxide (RuO ₄ ), and when the first phase is a polymer containing —NH ₂ or —CONH, the first Preferably, the stain is phosphotungstic acid. Also, when the second phase is polymethylmethacrylate (PMMA), _the second dye is preferably trimethylaluminum ( _{C6H18Al2 )} . At this time, the insulator that diffuses into the second phase is aluminum oxide (Al ₂ O ₃ ).

The fine wiring structure manufacturing method according to the embodiment of the present invention can be suitably carried out by the fine wiring structure manufacturing apparatus according to the embodiment of the present invention. An apparatus for manufacturing a fine wiring structure according to an embodiment of the present invention has heating means and diffusion means. The heating means is composed of, for example, a heater, and is configured to heat the phase-separated body arranged at a desired position so that the phase-separated body undergoes phase separation when heat is applied. The heating means can carry out the phase separation step of the fine wiring structure manufacturing method according to the embodiment of the present invention.

The diffusing means is configured to diffuse the conductor or the insulator into at least one of the phases separated by heating the phase-separated body with the heating means. The diffusing means can perform the diffusing step of the fine wiring structure manufacturing method according to the embodiment of the present invention. The diffusing means may be configured to diffuse the conductor or the insulator by, for example, using a dyeing method and immersing the phase-separated body phase-separated by the heating means in an aqueous solution containing a dye. It may be configured to diffuse the conductor or insulator by exposing the phase-separated body to vapor of the staining agent. In this case, a diffusion step of dyeing with a dye can be carried out.

The fine wiring structure manufacturing method and the fine wiring structure manufacturing apparatus according to the embodiments of the present invention are provided by diffusing a conductor or an insulator into at least one of the phases separated by heat treatment, thereby forming a phase that conducts electricity easily. and impermeable phases can be formed. As a result, it is possible to form a fine wiring in which the phase through which electricity is easily conducted is a conductor. Also, since the self-organization of the phase separation is used, nanometer-level fine wiring can be formed. The fine wiring structure manufacturing method and fine wiring structure manufacturing apparatus according to the embodiments of the present invention can form fine wiring such as through electrodes, bumps, and multilayer wiring.

Further, the method for manufacturing a fine wiring structure according to the embodiment of the present invention uses a relatively simple method as the diffusion step, so that the conventional method in which lithography and etching are repeated, or the method in which a polymer is modified with a metal is used. Fine wiring can be formed in a smaller number of steps compared to the method of performing a pre-process for manufacturing a product.

In the method for manufacturing a fine wiring structure according to the embodiment of the present invention, by mixing the phase separator into the solution, the solution can be easily arranged at a desired position in the phase separation step. In addition, by including the conductive particles in the solution, the conductive particles can be aggregated into at least one phase in the phase separation process, and the formation of fine wiring can be promoted. Further, the fine wiring structure manufacturing method and the fine wiring structure manufacturing apparatus according to the embodiment of the present invention use the dyeing method in the diffusion process or the diffusion means to relatively easily diffuse conductors and insulators. be able to.

The method for manufacturing a fine wiring structure according to the embodiment of the present invention has a removal step of removing the polymer present in the phase in which the conductor or insulator is diffused in the diffusion step when the phase-separated body contains a polymer. You may have An apparatus for manufacturing a fine wiring structure according to an embodiment of the present invention has a removing means for removing a polymer present in a phase in which a conductor or an insulator is diffused by a diffusing means when the phase-separated body contains a polymer. may In these cases, the removal step or means may leave only conductors or insulators. When the conductor is left, the electrical conductivity can be increased and the electrical resistance can be kept low, and when the insulator is left, the electrical conductivity can be decreased and electric leakage can be prevented.

Further, the method for manufacturing a fine wiring structure according to the embodiment of the present invention may have a reduction step of reducing the conductor diffused in the diffusion step. The apparatus for manufacturing a fine wiring structure according to the embodiment of the present invention may have reducing means for reducing the conductor diffused by the diffusing means. In these cases, by reducing the conductor in a reduction step or reduction means, a material with higher electrical conductivity and lower electrical resistance can be obtained.

A fine wiring structure was manufactured using the fine wiring structure manufacturing method according to the embodiment of the present invention. First, a PS-b-PMMA block copolymer containing polystyrene (PS) and polymethyl methacrylate (PMMA) was used as a phase separator. The molecular weight of each component of this block copolymer was PS 57,000 and PMMA 25,000. In this composition, when phase separation occurs, PMMA forms a cylindrical nanostructure surrounded by PS.

Also, Au-PMMA nanoparticles were used as particles containing a conductor. The Mn number average molecular weight of PMMA contained in the Au-PMMA nanoparticles used is Mn 15,000. Also, the PMMA coverage on Au is 92.2%. Also, the particle size of the Au nanoparticles is 2 to 5 nm.

PS-b-PMMA block copolymer 98 vol% and Au-PMMA nanoparticles 2 vol% were dissolved in 20-fold diluted pyridine and mixed, and the mixed solution was formed on a Si plate with a diameter of 3 μm. was injected into the pores and allowed to dry. Then, it was subjected to heat treatment at 280° C. for 120 minutes in vacuum to cause phase separation, and then immersed in Ru-containing water (RuO ₄ aqueous solution) for 3 days to form an induced self-assembled composite. The PS:PMMA ratio after mixing PS-b-PMMA and Au-PMMA is approximately 1:1.

A scanning microscope (SEM) photograph of a longitudinal section of the guided self-assembled composite formed in the pores is shown in FIG. FIG. 2 shows the result of energy dispersive X-ray analysis (EDX) of a part of the longitudinal section. As shown in FIG. 1, it was confirmed that the induced self-assembled composite had multiple cylindrical PMMA phases in the PS matrix phase. In addition, as shown in FIGS. 1(b), (d) and 2(d), continuous Au nano-wires with a length of about 520 nm exist in the PMMA phase. It was confirmed that Moreover, as shown in FIG. 1(c), it was confirmed that the PS was stained with Ru, and RuO ₂ was diffused in the PS phase.

Next, using a nanoprobe of a microdevice characterization device (Nanoprober "N-6000SS"; manufactured by Hitachi High-Technologies Co., Ltd.), the longitudinal section of the induced self-assembled composite formed in the pores was measured. Voltage, current, and resistance measurements were taken in a predetermined section of the inside. The measurement points are the Au nanowire, the Ru-stained PS phase, and between the PMMA phase and the PS phase. SEM photographs and measurement results at each measurement point are shown in FIGS. 3 to 5, respectively.

As shown in FIG. 3, when the Au nano-wire was measured twice, it was found that the current and voltage were proportional to each other, and the resistance value was approximately less than 5 MΩ. confirmed. From this result, it can be said that the Au nanowires have electrical conductivity. In addition, as shown in FIG. 4, the Ru-stained PS phase was measured twice. However, it was confirmed that the resistance value was also smaller than approximately 25 MΩ. From this result, it can be said that the PS phase dyed with Ru also has conductivity. As shown in Fig. 5, almost no current flows between the PMMA phase (insulator) and the PS phase even though a voltage is applied, and the resistance is very large, several TΩ. was confirmed. From this result, it can be said that the PMMA phase and the PS phase are insulated.

As described above, according to the fine wiring structure manufacturing method of the embodiment of the present invention, Au-PMMA nanoparticles were used to form fine wiring by Au nanowires in the PMMA phase (see FIG. 3). ). Fine wiring was also formed on the Ru-dyed PS phase (see FIG. 4). The Ru-stained PS phase has electrical conductivity regardless of the presence of Au nanowires in the PMMA phase. It is clear that wiring can be formed.

Claims (15)

A phase separation step of arranging a phase separation body that phase separates when heat is applied at a desired position, and performing a heat treatment on the phase separation body to cause phase separation;
and a diffusion step of diffusing a conductor or an insulator into at least one of the phases separated in the phase separation step. 2. The method of manufacturing a fine wiring structure according to claim 1, wherein said phase-separated material is composed of two or more kinds of polymers that phase-separate when heat is applied. 2. The method of manufacturing a fine wiring structure according to claim 1, wherein the phase separator is a block copolymer. 2. The method of manufacturing a fine wiring structure according to claim 1, wherein the phase separator is a block copolymer containing polystyrene (PS) and polymethyl methacrylate (PMMA). 5. The method for manufacturing a fine wiring structure according to any one of claims 2 to 4, further comprising a removing step of removing a polymer existing in a phase in which the conductor or the insulator is diffused in the diffusion step. . 6. The method of manufacturing a fine wiring structure according to claim 1, wherein said phase separation step places a solution containing said phase separated body at said desired position. 7. The method of manufacturing a fine wiring structure according to claim 6, wherein said solution contains conductive particles. In the diffusion step, the first phase among the phases separated in the phase separation step is dyed with a first dye, thereby diffusing the conductor into the first phase. The method for manufacturing a fine wiring structure according to any one of claims 1 to 7. the first phase consists of a polymer containing -CH=CH-, -CH ₂ -CH ₂ -, -NH ₂ or -CONH as a functional group;
9. The method of manufacturing a fine wiring structure according to claim 8, wherein the first dye is osmium tetroxide, ruthenium tetroxide, or phosphotungstic acid. the first phase is polystyrene (PS);
The first dye is ruthenium tetroxide,
9. The method of manufacturing a fine wiring structure according to claim 8, wherein the conductor is ruthenium dioxide. 11. The method of manufacturing a fine wiring structure according to claim 8, further comprising a reduction step of reducing the conductor diffused into the first phase in the diffusion step. In the diffusion step, the second phase among the phases separated in the phase separation step is dyed with a second dye, thereby diffusing the insulator into the second phase. The method for manufacturing a fine wiring structure according to any one of claims 1 to 11. the second phase is polymethyl methacrylate (PMMA);
the second staining agent is trimethylaluminum;
13. The method of manufacturing a fine wiring structure according to claim 12, wherein the insulator is aluminum oxide. a heating means for heating the phase-separated body arranged at a desired position so that the phase-separated body undergoes phase separation when heat is applied;
Diffusion means for diffusing a conductor or an insulator into at least one of the phases separated by heating the phase-separated body with the heating means,
An apparatus for manufacturing a fine wiring structure, comprising: The diffusing means diffuses the conductor or the insulator into at least one of the separated phases by exposing the phase-separated body phase-separated by the heating means to vapor of a staining agent. 15. The apparatus for manufacturing a fine wiring structure according to claim 14, wherein the apparatus is constructed as follows.

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