WO2007108132A1 - Process for producing carbon nanotube - Google Patents

Process for producing carbon nanotube Download PDF

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Publication number
WO2007108132A1
WO2007108132A1 PCT/JP2006/305866 JP2006305866W WO2007108132A1 WO 2007108132 A1 WO2007108132 A1 WO 2007108132A1 JP 2006305866 W JP2006305866 W JP 2006305866W WO 2007108132 A1 WO2007108132 A1 WO 2007108132A1
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WIPO (PCT)
Prior art keywords
substrate
fine particles
catalyst material
protrusions
carbon
Prior art date
Application number
PCT/JP2006/305866
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French (fr)
Japanese (ja)
Inventor
Akio Kawabata
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Fujitsu Limited
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Application filed by Fujitsu Limited filed Critical Fujitsu Limited
Priority to PCT/JP2006/305866 priority Critical patent/WO2007108132A1/en
Priority to JP2008506134A priority patent/JP4850900B2/en
Publication of WO2007108132A1 publication Critical patent/WO2007108132A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0238—Impregnation, coating or precipitation via the gaseous phase-sublimation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
    • B01J37/349—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of flames, plasmas or lasers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • C01B32/162—Preparation characterised by catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
    • B01J21/063—Titanium; Oxides or hydroxides thereof
    • B01J35/60—
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/20—Nanotubes characterized by their properties
    • C01B2202/36—Diameter

Definitions

  • the present invention relates to a method for producing carbon nanotubes, and more particularly to a method for producing carbon nanotubes that can be produced by crosslinking isolated carbon nanotubes.
  • Carbon nanotubes basically have a structure in which a dalaphen sheet with a hexagonal network structure of carbon atoms is rolled into a cylindrical shape.
  • SWNT single-walled nanotubes
  • DWNT double-walled single-bonn nanotubes
  • Carbon nanotubes with electrical or semiconducting electrical properties and semiconducting electrical properties can be expected to be applied to electronic devices.
  • Patent Document 1 proposes a structure of an electrode that is electrically connected to a multi-walled carbon nanotube. According to this, the carbon nanotube is cut immediately before forming the electrode, and a metal that forms a strong and ionic bond with the carbon atom is formed on the cut carbon nanotube to form the electrode. As a result, the contact resistance between the electrode and the carbon nanotube is reduced, and it is attempted to be applied to electronic devices!
  • Patent Document 2 proposes a field effect transistor in which a metallic inner layer of a double-walled carbon nanotube is used as a gate electrode and a semiconducting outer layer is used as a channel. Patent Document 2 also discloses a field effect transistor in which a semiconducting inner layer of two-walled carbon nanotubes is used as a channel region and a metallic outer layer is used as a gate electrode as a prior art.
  • carbon nanotubes need to be generated in a state of being isolated and hanging in a hollow state without contacting the substrate. If the carbon nanotubes are in contact with the substrate, the characteristic evaluation signal will be weak, and if multiple carbon nanotubes are bundled (bundled), fluorescence will not be seen. This is because evaluation becomes difficult. Therefore, the present condition is to select the carbon nanotubes that are in a state of floating in the air alone from the many grown carbon nanotubes, and to characterize them. However, if the force grows in a bundled state, it becomes difficult to take out single bonn nanotubes with the desired characteristics and support them on the substrate.
  • Patent Document 3 fine protrusions are formed on the surface of a silicon substrate, a portion other than the protrusion tips is coated with a photosensitive resist, a catalyst metal is applied only to the protrusion tips, and a desired metal is applied to the catalyst metal by CVD.
  • the production of carbon nanotubes of diameter is described. According to this method, it is expected to generate carbon nanotubes with the tip force of the protrusions, and it is expected to reproduce the state of being hung alone.
  • Patent Literature l WO 02 / 063693A1
  • Patent Document 2 JP 2004-171903 A
  • Patent Document 3 Japanese Patent Application Laid-Open No. 2004-182537
  • Patent Document 3 The generation method of Patent Document 3 described above requires a process of forming protrusions on the surface of the silicon substrate, and covering with a photosensitive resist leaving the tip. However, in this process, it is necessary to control the height of the protrusion and the film thickness of the photosensitive resist with high precision, which is not a realistic generation method. Depending on the size of the catalyst metal formed at the tip of the protrusion, the growth Although the diameter and the number of layers of the carbon nanotubes can be controlled, it is difficult to control the size of the catalyst metal with good reproducibility for the same reason as above.
  • an object of the present invention is to provide a carbon nanotube production method capable of producing a large amount of hollow carbon nanotubes with good reproducibility.
  • a first step of preparing a first substrate having a plurality of protrusions formed on the surface, and a second substrate A second step of generating a plurality of fine particles comprising a catalyst material, and contacting a plurality of protrusions formed on the first substrate with the fine particles of the catalyst material formed on the second substrate, A third step of attaching the fine particles of the catalyst material to the plurality of protrusions, and a fourth step of growing the carbon nanotubes on the fine particles of the catalyst material by placing the first substrate in a carbon-containing gas atmosphere. It is the production method of the carbon nanotube which has.
  • the catalyst material is a transition metal containing at least cobalt, iron, and nickel.
  • the catalyst material is an alloy of a transition metal containing at least cobalt, iron, or nickel and a metal of Ti, Al, Ta, TiN, or Ti02.
  • the protrusion of the first substrate is in contact with the fine particles of the catalyst material of the second substrate. , Heat to a predetermined temperature to attach fine particles of catalyst material to the protrusions.
  • Ti, Al are formed on the plurality of protrusion surfaces of the first substrate prepared in the first step.
  • the transition material fine particles are transition metal fine particles having a diameter of 0.5 to LOnm, and the carbon nanotubes grown in the fourth step are 1 to 4nm in diameter. Single or double layered in diameter.
  • a first step of preparing a first substrate having a plurality of protrusions formed on the surface, and a step on the second substrate Made of catalyst material A second step of generating a plurality of fine particles; and a plurality of protrusions formed on the first substrate are brought into contact with the fine particles of the catalyst material formed on the second substrate;
  • a method for producing a fine wire substance comprising: a third step of attaching fine particles of material; and a fourth step of placing the first substrate in a growth gas atmosphere to grow fine wire substance on the fine particles of the catalyst material. is there.
  • the catalyst material is Au
  • the fine wire substance is a group IIIV compound semiconductor containing GaAs, InP, InAs, and a fourth process force.
  • This is a metalorganic chemical vapor deposition method using III group V metal gas as the growth gas.
  • a first step of generating a plurality of fine particles of a catalyst material on a substrate Etching with the fine particles as a mask to form a plurality of protrusions having the fine particles attached to the tips, and placing the substrate in a growth gas atmosphere to grow fine wire substances on the fine particles of the catalyst material
  • a third step of producing a fine wire substance a first step of generating a plurality of fine particles of a catalyst material on a substrate, Etching with the fine particles as a mask to form a plurality of protrusions having the fine particles attached to the tips, and placing the substrate in a growth gas atmosphere to grow fine wire substances on the fine particles of the catalyst material.
  • FIG. 1 is a cross-sectional view showing a carbon nanotube production process according to the first embodiment.
  • FIG. 2 is a cross-sectional view showing a carbon nanotube production process according to the first embodiment. It is a figure explaining the laser abrasion method.
  • FIG. 4 is a cross-sectional view showing a production process of carbon nanotubes according to the first embodiment
  • FIG. 5 is a sectional view showing a carbon nanotube production step according to the first embodiment.
  • FIG. 6 is a cross-sectional view showing a carbon nanotube production step according to the first embodiment.
  • FIG. 7 is a schematic configuration diagram of a CVD apparatus.
  • FIG. 8 is a view showing a carbon nanotube CNT generated by the third embodiment.
  • FIG. 9 is a cross-sectional view showing a production process of the fifth embodiment.
  • FIGS. 1, 2, 4, 4, and 6 are cross-sectional views showing the carbon nanotube production process according to the first embodiment.
  • a substrate having a plurality of fine needle-like protrusions 12 formed on the surface for example, a silicon substrate 10 is prepared.
  • the fine protrusions 12 are formed, for example, by forming a resist layer having a predetermined pattern on the surface of the silicon substrate 10 and etching the substrate surface using the mask as a mask to form irregularities having a rectangular cross section. This can be achieved by processing the concavo-convex protrusion into a protrusion 12 with a sharp tip by a wet etching method having anisotropy in a predetermined crystal direction.
  • fine particles 22 of catalyst material are supported on the surface of a substrate 20 such as silicon.
  • This catalyst material is a transition metal containing, for example, nickel, iron, and cobalt when growing carbon nanotubes. Or transition metal and Ti,
  • the diameter of the fine particles is controlled to about 0.5 to: LOnm, preferably about 1 to 4 nm.
  • Fine particles whose diameter is controlled to about LOnm are generated on the substrate surface by the laser ablation method developed by the present inventors.
  • the method of producing these fine particles is It is introduced in detail in Chemical Physics Letters 382 (2003) 361.
  • FIG. 3 is a diagram for explaining the laser ablation method. The method is briefly described below.
  • an iron target 32 is set in a chamber 30 containing He gas and having a pressure of 1.5 KPa, and the target is irradiated with a laser beam 36 from an Nd, YAG laser 34 to ablate the iron target 32 ( Excise).
  • the iron of the target 32 evaporates by irradiation with a single laser beam 36 having energy, and immediately after that, solidifies to produce fine particles 40. These fine particles are annealed when passing through the vicinity of the tube-shaped heating means 42 by the He gas flow, and the crystal state thereof is improved.
  • the particle size of the iron fine particles 40 to be generated has a certain variation, the particle size is 0.5 to: LOnm, preferably 1.0 to 4 by DM A (Differential Mobility Analyzer) 44.
  • Fine particles having a particle size of Onm are selected, introduced into the chamber 46, and supported on the surface of the second substrate 20 as fine particles 22 of the catalyst material.
  • a voltage is applied to the stage 28 of the substrate 20, and the charged fine particles 22 fall on the surface of the substrate 20 due to a potential difference.
  • the first substrate 10 having a plurality of protrusions formed on the surface is turned upside down so as to face the second substrate 20 carrying a large number of fine particles 22 of catalyst material. Then, the tip of the protrusion 12 is brought into contact with the fine particle 22 to attach the fine particle 22 to the tip of the protrusion. As a result, as shown in FIG. 5, one particle 22 is attached to the tip of the protrusion 12 of the first substrate 10.
  • the fine particles can be more efficiently attached to the tips of the protrusions by heating to, for example, about 300 ° C. while the tips of the protrusions 12 are in contact with the fine particles 22.
  • This heating temperature is considerably lower than the melting point of catalytic metals such as iron, but the metal is easily attached by heating.
  • the fine particles 22 are supported on the surface of the substrate 20 without gaps. However, if there are gaps between the fine particles 22 to some extent, the projection 12 is more effective in the adhesion process of FIG.
  • One fine particle 22 can be separated and attached to the tip of the substrate. As described above, the particle size of the catalyst metal fine particles 22 is adjusted to a desired value, and by using the catalyst metal fine particles 22 having such a controlled particle size, carbon nanotubes having a uniform diameter are grown. To let it can. Therefore, it is desirable to attach a single particle 22 to the tip of each protrusion.
  • the first substrate is introduced into the chamber of the thermal CVD apparatus, and while the substrate is heated to about 600 ° C., argon (Ar), acetylene (C2H2), hydrogen Carbon nanotubes CNT are grown on the catalytic metal fine particles 22 in an atmosphere of 0.1 to lKPa in a mixed gas of (H2) (ratio 90: 10: 1000). Carbon nanotubes CNT start growing at a diameter corresponding to the particle size of the fine particles 22, and the tip reaches the surface of the adjacent protrusion.
  • Ar argon
  • C2H2 acetylene
  • the length of the carbon nanotube CNT can be controlled, and the carbon nanotube isolated in the hollow from the catalytic metal fine particle 22 to the adjacent protrusion 22 CNT can be grown.
  • FIG. 7 is a schematic configuration diagram of the above CVD apparatus.
  • a stage 52 and a heating means 54 made of hot filament are provided in a chamber 50.
  • a voltage 56 is applied to the hot filament 54 to generate heat, and the surface of the first substrate placed on the stage 52 is heated.
  • a mixed gas of argon (Ar), acetylene (C2H2), and hydrogen (H2) (ratio 90: 10: 1000) 58 is introduced into the chamber 50 as the growth gas. maintained at lKPa.
  • Ar argon
  • C2H2H2H2 acetylene
  • H2H2H2 hydrogen
  • the surface of the first substrate 10 is heated to about 600 ° C.
  • carbon nanotube CNTs grow from the catalytic metal particles 22.
  • the present inventors by adjusting the diameter of the iron fine particles 22 to about 0.5 to 4 nm, it was possible to grow one or two-layer carbon nanotubes with a diameter of about 1 to 4 nm. Therefore, by attaching a single iron fine particle 22 to the tip 12, carbon nanotubes having a uniform diameter and a uniform number of layers can be generated in isolation.
  • transition metals such as iron, cobalt, and nickel were used as catalyst materials.
  • a mixture of these catalyst metals and any one of Ti, Al, Ta, TIN, and Ti02 is used. Therefore, the target 32 shown in Fig. 3 is replaced with the above mixed metal material.
  • the mixed metal fine particles 22 can be supported on the surface of the second substrate 20 by the same manufacturing method.
  • Other processes are the same as those in the first implementation. The form is the same.
  • fine particles mixed with both metals are generated by laser ablation using a mixed substrate of 80% coronate and 20% titanium as the target 32.
  • a metal film of Ti, Al, Ta, TiN, or Ti02 is deposited on the surface of the needle-like protrusion 12 of the first substrate 10 shown in FIG. It is formed to a film thickness of about.
  • catalytic metal fine particles 22 such as cobalt are attached to the protrusions 12 according to the procedures shown in FIGS. 2, 4, and 5, and carbon nanotubes are grown by thermal CVD or hot filament CVD.
  • FIG. 8 is a diagram showing the carbon nanotube CNT generated by the third embodiment.
  • a titanium film 12 is formed on the surface of the needle-like protrusion 12, and carbon nanotubes CNT grow on cobalt fine particles 22 attached on the titanium film 12.
  • the substrate is heated to, for example, 650 ° C, a mixed gas of alcohol and hydrogen such as argon and ethanol is introduced, maintained at a pressure of 0.1 KPa, and held for about 40 minutes.
  • the growing carbon nanotube CNT forms an ohmic contact with low resistance between the titanium film 12.
  • the tip of the growing carbon nanotube CNT also forms a low-resistance ohmic contact with the titanium film.
  • the cobalt fine particles may be fine particles of other transition metals, fine particles of a mixture of transition metal and Ti, Al, Ta, TiN, Ti02 (V, any metal!
  • the carbon nanotube generation method has been described.
  • it is a method for producing a thin wire material that is not a carbon nanotube but a IIIV compound semiconductor.
  • a first substrate 10 having needle-like protrusions 12 is prepared.
  • the second A catalyst metal for example, gold fine particles 22 is supported on the surface of the substrate 20. 4 and 5, gold fine particles 22 are attached to the tips of the protrusions 12 of the first substrate 10.
  • the first substrate is loaded into the MOCVD (Metal Organic Chemical Vapor Deposition) equipment, and the fine wire material, III-V compound semiconductor, is grown on the catalyst particles 22 in the III-V metal gas atmosphere. Let Similar to the carbon nanotube CNT shown in Fig. 6, this fine wire material grows from catalyst fine particles 22 and becomes a thin rod-like material that reaches the surface of the adjacent protrusion 12.
  • MOCVD Metal Organic Chemical Vapor Deposition
  • FIG. 9 is a cross-sectional view showing the generation process of the fifth embodiment.
  • step (a) fine particles 22 of the catalyst material are generated on the surface of the first substrate 10 by the method described above.
  • step (b) using the fine particles 22 as a mask, the surface of the first substrate 10 is etched by, for example, ion milling to form needle-like protrusions 12.
  • step (b) using the fine particles 22 as a mask, the surface of the first substrate 10 is etched by, for example, ion milling to form needle-like protrusions 12.
  • this is the same state as in Fig. 5.
  • the growth gas for chemical vapor deposition in the first to fifth embodiments described above may be a gas obtained by vaporizing a carbon-containing liquid in addition to acetylene and alcohol.
  • nitrogen may also be used.
  • N2 may be used, and in addition to argon Ar, helium He may be used.
  • a gas obtained by vaporizing a carbon-containing liquid such as hydrocarbon or alcohol may be used alone, or a mixed gas mixed with at least one of hydrogen, nitrogen, argon, and helium may be used. You can use it.

Abstract

A process for producing carbon nanotubes, comprising providing first substrate (10) furnished with multiple projections on its surface; forming multiple microparticles of a catalyst material on a second substrate; bringing the multiple projections (12) on the first substrate into contact with the catalyst material microparticles on the second substrate to thereby adhere the catalyst material microparticles to the multiple projections; and placing the first substrate in a carbonaceous gas atmosphere to thereby grow carbon nanotubes on the catalyst material microparticles. Thus, carbon nanotubes isolated between projections are formed.

Description

明 細 書  Specification
カーボンナノチューブの生成方法  Method for producing carbon nanotubes
技術分野  Technical field
[0001] 本発明は，カーボンナノチューブの生成方法に関し，特に，孤立したカーボンナノ チューブを架橋させて生成することができるカーボンナノチューブの生成方法に関す る。  The present invention relates to a method for producing carbon nanotubes, and more particularly to a method for producing carbon nanotubes that can be produced by crosslinking isolated carbon nanotubes.
背景技術  Background art
[0002] カーボンナノチューブ（Carbon Nano-Tube： CNT)を用いた電子素子の研究が盛 んに行われている。カーボンナノチューブは，炭素原子の六角形の網目構造のダラ フェンシートを円筒状に丸めた構造を基本とする。カーボンナノチューブは，微細化 されて単層カーボンナノチューブ（シングルウォールナノチューブ（SWNT))や 2層力 一ボンナノチューブ（ダブルウォールナノチューブ（DWNT))になると，その直径や力 イラリティの違!ヽから金属的電気特性または半導体的電気特性を有し，半導体的電 気特性のカーボンナノチューブは，電子デバイスへの適用が期待できる。未だに基 礎的な研究段階ではあるが，カーボンナノチューブの電子デバイスへの適用例が種 々報告されている。  [0002] Research on electronic devices using carbon nano-tubes (CNTs) has been actively conducted. Carbon nanotubes basically have a structure in which a dalaphen sheet with a hexagonal network structure of carbon atoms is rolled into a cylindrical shape. When carbon nanotubes are miniaturized to become single-walled carbon nanotubes (single-walled nanotubes (SWNT)) or double-walled single-bonn nanotubes (double-walled nanotubes (DWNT)), the difference in diameter and strength is due to the difference in irritation. Carbon nanotubes with electrical or semiconducting electrical properties and semiconducting electrical properties can be expected to be applied to electronic devices. Although it is still a basic research stage, various examples of application of carbon nanotubes to electronic devices have been reported.
[0003] 例えば，特許文献 1では，多層カーボンナノチューブに電気的に接続される電極の 構造が提案されている。これによれば，電極を形成する直前にカーボンナノチューブ を切削し，炭素原子と強 、ィヒ学結合をする金属を切削したカーボンナノチューブ上 に形成して電極を形成する。それにより，電極とカーボンナノチューブとの接触抵抗 を低減して電子デバイスへの適用を試みて!/、る。  [0003] For example, Patent Document 1 proposes a structure of an electrode that is electrically connected to a multi-walled carbon nanotube. According to this, the carbon nanotube is cut immediately before forming the electrode, and a metal that forms a strong and ionic bond with the carbon atom is formed on the cut carbon nanotube to form the electrode. As a result, the contact resistance between the electrode and the carbon nanotube is reduced, and it is attempted to be applied to electronic devices!
[0004] また，特許文献 2では， 2層カーボンナノチューブの金属性の内層をゲート電極にし ,半導体性の外層をチャネルにした電界効果トランジスタが提案されている。また，特 許文献 2には先行技術として , 2層のカーボンナノチューブの半導体性の内層をチヤ ネル領域にし，金属性の外層をゲート電極とした電界効果トランジスタも開示されて いる。  [0004] Patent Document 2 proposes a field effect transistor in which a metallic inner layer of a double-walled carbon nanotube is used as a gate electrode and a semiconducting outer layer is used as a channel. Patent Document 2 also discloses a field effect transistor in which a semiconducting inner layer of two-walled carbon nanotubes is used as a channel region and a metallic outer layer is used as a gate electrode as a prior art.
[0005] 上記の通りカーボンナノチューブを利用した電子デバイスへの応用が報告されてい るが，半導体的性質を有する単層または 2層のカーボンナノチューブを再現性良く製 造する方法は，未だ数える程度しか報告されていない。そして，再現性良く半導体的 性質を有する単層または 2層のカーボンナノチューブを生成することは未だに困難で あるので，ランダムに生成された多数のカーボンナノチューブをラマン分光や蛍光特 性を評価し，所望の特性を有するカーボンナノチューブを選択して，電子デバイスの 形成に利用するにとどまつている。 [0005] As described above, application to electronic devices using carbon nanotubes has been reported. However, only a few methods have been reported to produce single- or double-walled carbon nanotubes with semiconducting properties with good reproducibility. Since it is still difficult to produce single-walled or double-walled carbon nanotubes with semiconducting properties with good reproducibility, Raman spectroscopy and fluorescence characteristics of many randomly generated carbon nanotubes were evaluated and desired Carbon nanotubes with these characteristics are selected and used only for the formation of electronic devices.
[0006] ラマン分光や蛍光特性の評価のためには，カーボンナノチューブが基板に接触す ることなく孤立して中空にぶら下がった状態で生成される必要がある。カーボンナノチ ユーブが基板に接触していると特性評価の信号が弱くなつたり，複数のカーボンナノ チューブがバンドルイ匕している（束になっている）と蛍光が見られなくなったりして，特 性評価が困難になるからである。したがって，成長した多数のカーボンナノチューブ のうち単独で中空に浮いた状態にあるカーボンナノチューブを選択し，それを特性評 価しているのが現状である。し力も，バンドル化した状態で成長すると，所望特性の力 一ボンナノチューブを 1個単位で取り出して基板上に担持することが困難になる。  [0006] In order to evaluate Raman spectroscopy and fluorescence characteristics, carbon nanotubes need to be generated in a state of being isolated and hanging in a hollow state without contacting the substrate. If the carbon nanotubes are in contact with the substrate, the characteristic evaluation signal will be weak, and if multiple carbon nanotubes are bundled (bundled), fluorescence will not be seen. This is because evaluation becomes difficult. Therefore, the present condition is to select the carbon nanotubes that are in a state of floating in the air alone from the many grown carbon nanotubes, and to characterize them. However, if the force grows in a bundled state, it becomes difficult to take out single bonn nanotubes with the desired characteristics and support them on the substrate.
[0007] 特許文献 3では，シリコン基板表面に微細な突起を形成し，感光性レジストで突起 先端以外を被覆し，突起の先端のみに触媒金属を塗布し， CVD法によりその触媒 金属に所望の直径のカーボンナノチューブを生成することが記載されている。この方 法によれば，突起の先端力 カーボンナノチューブを生成することが期待でき，単独 で中空にぶら下がった状態を再現することが期待される。  [0007] In Patent Document 3, fine protrusions are formed on the surface of a silicon substrate, a portion other than the protrusion tips is coated with a photosensitive resist, a catalyst metal is applied only to the protrusion tips, and a desired metal is applied to the catalyst metal by CVD. The production of carbon nanotubes of diameter is described. According to this method, it is expected to generate carbon nanotubes with the tip force of the protrusions, and it is expected to reproduce the state of being hung alone.
特許文献 l :WO 02/063693A1  Patent Literature l: WO 02 / 063693A1
特許文献 2 :特開 2004— 171903号公報  Patent Document 2: JP 2004-171903 A
特許文献 3 :特開 2004— 182537号公報  Patent Document 3: Japanese Patent Application Laid-Open No. 2004-182537
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0008] 上記の特許文献 3の生成方法では，シリコン基板表面に突起を形成し，その先端を 残して感光体レジストで被覆する工程が必要になる。しカゝしながら，この工程では突 起の高さと感光体レジストの膜厚とを高精度に制御する必要があり，現実的な生成方 法とはいえない。そして，突起先端に形成される触媒金属の大きさに依存して，成長 するカーボンナノチューブの直径，層数が制御されうるが，上記と同じ理由で触媒金 属の大きさを再現性良く制御することは困難である。 [0008] The generation method of Patent Document 3 described above requires a process of forming protrusions on the surface of the silicon substrate, and covering with a photosensitive resist leaving the tip. However, in this process, it is necessary to control the height of the protrusion and the film thickness of the photosensitive resist with high precision, which is not a realistic generation method. Depending on the size of the catalyst metal formed at the tip of the protrusion, the growth Although the diameter and the number of layers of the carbon nanotubes can be controlled, it is difficult to control the size of the catalyst metal with good reproducibility for the same reason as above.
[0009] そこで，本発明の目的は， 中空に孤立化したカーボンナノチューブを大量に且つ 再現性良く生成することができるカーボンナノチューブの生成方法を提供することに ある。  Accordingly, an object of the present invention is to provide a carbon nanotube production method capable of producing a large amount of hollow carbon nanotubes with good reproducibility.
課題を解決するための手段  Means for solving the problem
[0010] 上記の目的を達成するために，本発明の第 1の側面によれば，表面に複数の突起 が形成された第 1の基板を準備する第 1の工程と，第 2の基板上に触媒材料からなる 微粒子を複数個生成する第 2の工程と，前記第 1の基板に形成された複数の突起を 前記第 2の基板上に形成された触媒材料の微粒子に接触させて， 当該複数の突起 に触媒材料の微粒子を付着させる第 3の工程と，前記第 1の基板を炭素含有ガス雰 囲気中に置 、て前記触媒材料の微粒子にカーボンナノチューブを成長させる第 4の 工程とを有するカーボンナノチューブの生成方法である。  [0010] To achieve the above object, according to the first aspect of the present invention, there is provided a first step of preparing a first substrate having a plurality of protrusions formed on the surface, and a second substrate. A second step of generating a plurality of fine particles comprising a catalyst material, and contacting a plurality of protrusions formed on the first substrate with the fine particles of the catalyst material formed on the second substrate, A third step of attaching the fine particles of the catalyst material to the plurality of protrusions, and a fourth step of growing the carbon nanotubes on the fine particles of the catalyst material by placing the first substrate in a carbon-containing gas atmosphere. It is the production method of the carbon nanotube which has.
[0011] 上記の第 1の側面において，好ましい態様によれば，前記触媒材料が，少なくとも コバルト，鉄，ニッケルを含む遷移金属である。または，前記触媒材料が，少なくとも コバルト，鉄，ニッケルを含む遷移金属と， Ti, Al, Ta, TiN, Ti02のいずれかの金 属とを合金化したものである。  [0011] In the first aspect described above, according to a preferred embodiment, the catalyst material is a transition metal containing at least cobalt, iron, and nickel. Alternatively, the catalyst material is an alloy of a transition metal containing at least cobalt, iron, or nickel and a metal of Ti, Al, Ta, TiN, or Ti02.
[0012] さらに，上記の第 1の側面において，好ましい態様によれば，前記第 3の工程で，前 記第 1の基板の突起を前記第 2の基板の触媒材料の微粒子に接触した状態で，所 定の温度に加熱して前記突起に触媒材料の微粒子を付着させる。  [0012] Further, according to a preferred aspect of the first aspect described above, in the third step, the protrusion of the first substrate is in contact with the fine particles of the catalyst material of the second substrate. , Heat to a predetermined temperature to attach fine particles of catalyst material to the protrusions.
[0013] さらに，上記の第 1の側面において，好ましい態様によれば，前記第 3の工程の前 に，前記第 1の工程で準備した第 1の基板の複数の突起表面に， Ti, Al, Ta, TiN, Ti02( V、ずれかの金属層を形成する第 5の工程を有する。  [0013] Further, in the first aspect described above, according to a preferred embodiment, prior to the third step, Ti, Al are formed on the plurality of protrusion surfaces of the first substrate prepared in the first step. , Ta, TiN, Ti02 (V, having a fifth step of forming a metal layer of any one.
[0014] 第 1の側面において，好ましくは，前記遷移材料の微粒子が， 0. 5〜： LOnmの径を 有する遷移金属微粒子であり，前記第 4の工程で成長するカーボンナノチューブが 1 〜4nmの直径で単層または 2層構造である。  [0014] In the first aspect, preferably, the transition material fine particles are transition metal fine particles having a diameter of 0.5 to LOnm, and the carbon nanotubes grown in the fourth step are 1 to 4nm in diameter. Single or double layered in diameter.
[0015] 上記の目的を達成するために，本発明の第 2の側面によれば，表面に複数の突起 が形成された第 1の基板を準備する第 1の工程と，第 2の基板上に触媒材料からなる 微粒子を複数個生成する第 2の工程と，前記第 1の基板に形成された複数の突起を 前記第 2の基板上に形成された触媒材料の微粒子に接触させて， 当該複数の突起 に触媒材料の微粒子を付着させる第 3の工程と，前記第 1の基板を成長ガス雰囲気 中に置 、て前記触媒材料の微粒子に細線物質を成長させる第 4の工程とを有する 細線物質の生成方法である。 [0015] In order to achieve the above object, according to the second aspect of the present invention, a first step of preparing a first substrate having a plurality of protrusions formed on the surface, and a step on the second substrate Made of catalyst material A second step of generating a plurality of fine particles; and a plurality of protrusions formed on the first substrate are brought into contact with the fine particles of the catalyst material formed on the second substrate; A method for producing a fine wire substance, comprising: a third step of attaching fine particles of material; and a fourth step of placing the first substrate in a growth gas atmosphere to grow fine wire substance on the fine particles of the catalyst material. is there.
[0016] 上記第 2の側面において，好ましい態様によれば，前記触媒材料が Auであり，前 記細線物質が GaAs, InP, InAsを含む III V属の化合物半導体であり，第 4の工程 力 III V属の金属ガスを成長ガスとして使用する有機金属化学気相成長法である [0016] In the second aspect, according to a preferred embodiment, the catalyst material is Au, and the fine wire substance is a group IIIV compound semiconductor containing GaAs, InP, InAs, and a fourth process force. This is a metalorganic chemical vapor deposition method using III group V metal gas as the growth gas.
[0017] 上記の目的を達成するために，本発明の第 3の側面によれば，基板上に触媒材料 からなる微粒子を複数個生成する第 1の工程と，前記基板の表面を前記複数の微粒 子をマスクにしてエッチングして，先端に前記微粒子が付着した複数の突起を形成 する第 2の工程と，前記基板を成長ガス雰囲気中に置いて前記触媒材料の微粒子 に細線物質を成長させる第 3の工程とを有する細線物質の生成方法である。 [0017] In order to achieve the above object, according to a third aspect of the present invention, a first step of generating a plurality of fine particles of a catalyst material on a substrate, Etching with the fine particles as a mask to form a plurality of protrusions having the fine particles attached to the tips, and placing the substrate in a growth gas atmosphere to grow fine wire substances on the fine particles of the catalyst material And a third step of producing a fine wire substance.
発明の効果  The invention's effect
[0018] 本発明によれば，第 1の基板の突起の先端に触媒材料の微粒子を付着させるので ,そこに孤立したカーボンナノチューブまたは細線物質を再現性良く成長させること ができる。  [0018] According to the present invention, since the fine particles of the catalyst material are attached to the tips of the protrusions of the first substrate, it is possible to grow isolated carbon nanotubes or fine wire substances there with good reproducibility.
図面の簡単な説明  Brief Description of Drawings
[0019] [図 1]第 1の実施の形態によるカーボンナノチューブの生成工程を示す断面図である [図 2]第 1の実施の形態によるカーボンナノチューブの生成工程を示す断面図である [図 3]レーザーアブレーシヨン法を説明する図である。  FIG. 1 is a cross-sectional view showing a carbon nanotube production process according to the first embodiment. FIG. 2 is a cross-sectional view showing a carbon nanotube production process according to the first embodiment. It is a figure explaining the laser abrasion method.
[図 4]第 1の実施の形態によるカーボンナノチューブの生成工程を示す断面図である  FIG. 4 is a cross-sectional view showing a production process of carbon nanotubes according to the first embodiment
[図 5]第 1の実施の形態によるカーボンナノチューブの生成工程を示す断面図である [図 6]第 1の実施の形態によるカーボンナノチューブの生成工程を示す断面図である FIG. 5 is a sectional view showing a carbon nanotube production step according to the first embodiment. FIG. 6 is a cross-sectional view showing a carbon nanotube production step according to the first embodiment.
[図 7]CVD装置の概略構成図である。 FIG. 7 is a schematic configuration diagram of a CVD apparatus.
[図 8]第 3の実施の形態により生成されたカーボンナノチューブ CNTを示す図である  FIG. 8 is a view showing a carbon nanotube CNT generated by the third embodiment.
[図 9]第 5の実施の形態の生成工程を示す断面図である。 FIG. 9 is a cross-sectional view showing a production process of the fifth embodiment.
符号の説明  Explanation of symbols
[0020] 10 :第 1の基板 12 :突起 [0020] 10: First substrate 12: Projection
22 :触媒材料の微粒子 CNT:カーボンナノチューブ  22: Fine particles of catalyst material CNT: Carbon nanotube
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0021] 以下，図面にしたがって本発明の実施の形態について説明する。但し，本発明の 技術的範囲はこれらの実施の形態に限定されず，特許請求の範囲に記載された事 項とその均等物まで及ぶものである。  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and their equivalents.
[0022] [第 1の実施の形態]  [0022] [First embodiment]
図 1,図 2,図 4,図 5,図 6は，第 1の実施の形態によるカーボンナノチューブの生 成工程を示す断面図である。図 1の工程では，表面に複数の微細な針状の突起 12 が形成された基板，例えばシリコン基板 10を準備する。この微細な突起 12の形成は ,例えば，シリコン基板 10の表面に所定のパターンのレジスト層を形成し，それをマ スクにして基板表面をエッチングして矩形断面を有する凹凸を形成し，レジスト層を 除去して，所定の結晶方向に異方性を有するウエットエッチング法により凹凸の凸部 を先端が鋭角な突起 12に加工することで可能である。  FIGS. 1, 2, 4, 4, and 6 are cross-sectional views showing the carbon nanotube production process according to the first embodiment. In the process of FIG. 1, a substrate having a plurality of fine needle-like protrusions 12 formed on the surface, for example, a silicon substrate 10 is prepared. The fine protrusions 12 are formed, for example, by forming a resist layer having a predetermined pattern on the surface of the silicon substrate 10 and etching the substrate surface using the mask as a mask to form irregularities having a rectangular cross section. This can be achieved by processing the concavo-convex protrusion into a protrusion 12 with a sharp tip by a wet etching method having anisotropy in a predetermined crystal direction.
[0023] 図 1の工程とべつに，図 2の工程では，シリコンなどの基板 20の表面に触媒材料の 微粒子 22を担持させる。この触媒材料は，カーボンナノチューブを成長させる場合 は，例えば，ニッケル，鉄，コバルトを含む遷移金属である。または，遷移金属と Ti, In addition to the process of FIG. 1, in the process of FIG. 2, fine particles 22 of catalyst material are supported on the surface of a substrate 20 such as silicon. This catalyst material is a transition metal containing, for example, nickel, iron, and cobalt when growing carbon nanotubes. Or transition metal and Ti,
Al, Ta, TiN, Ti02のいずれかの金属とを混合して合金化したものである。この微粒 子の径は 0. 5〜： LOnm,好ましくは l〜4nm程度に制御されたものである。 It is an alloy formed by mixing any one of Al, Ta, TiN and Ti02. The diameter of the fine particles is controlled to about 0.5 to: LOnm, preferably about 1 to 4 nm.
[0024] 図 2のように 0. 5〜： LOnm程度に径が制御された微粒子は，本発明者らが開発した レーザーアブレーシヨン法により基板表面に生成される。この微粒子の生成方法は， Chemical Physics Letters 382 (2003) 361に詳細に紹介されている。 As shown in FIG. 2, 0.5˜: Fine particles whose diameter is controlled to about LOnm are generated on the substrate surface by the laser ablation method developed by the present inventors. The method of producing these fine particles is It is introduced in detail in Chemical Physics Letters 382 (2003) 361.
[0025] 図 3は，上記のレーザーアブレーシヨン法を説明する図である。以下，その方法を 簡単に説明する。まず， Heガスを含み圧力が 1. 5KPaのチャンバ一 30内に鉄のタ 一ゲット 32をセットし，そのターゲットに Nd, YAGレーザ 34からのレーザービーム 36 を照射して鉄ターゲット 32をアブレーシヨン (切除)する。エネルギーを有するレーザ 一ビーム 36の照射によりターゲット 32の鉄が蒸発し，その直後に固化して微粒子 40 が生成される。この微粒子は， Heガス流によってチューブ状の加熱手段 42の近傍を 通過するときにァニールされその結晶状態が改善される。 FIG. 3 is a diagram for explaining the laser ablation method. The method is briefly described below. First, an iron target 32 is set in a chamber 30 containing He gas and having a pressure of 1.5 KPa, and the target is irradiated with a laser beam 36 from an Nd, YAG laser 34 to ablate the iron target 32 ( Excise). The iron of the target 32 evaporates by irradiation with a single laser beam 36 having energy, and immediately after that, solidifies to produce fine particles 40. These fine particles are annealed when passing through the vicinity of the tube-shaped heating means 42 by the He gas flow, and the crystal state thereof is improved.
[0026] ただし，生成される鉄の微粒子 40の粒径は一定のばらつきをもっているので， DM A (Differential Mobility Analyzer)44により，粒径が 0. 5〜： LOnm,望ましくは 1. 0〜 4. Onmの粒径を有する微粒子が選択され，チャンバ一 46内に導かれ，触媒材料の 微粒子 22として第 2の基板 20の表面に担持される。第 2の基板 20の表面に微粒子 2 2を積もらせるために，基板 20のステージ 28には電圧が印加され，帯電した微粒子 2 2が電位差によって基板 20の表面に降り積もる。 [0026] However, since the particle size of the iron fine particles 40 to be generated has a certain variation, the particle size is 0.5 to: LOnm, preferably 1.0 to 4 by DM A (Differential Mobility Analyzer) 44. Fine particles having a particle size of Onm are selected, introduced into the chamber 46, and supported on the surface of the second substrate 20 as fine particles 22 of the catalyst material. In order to accumulate the fine particles 22 on the surface of the second substrate 20, a voltage is applied to the stage 28 of the substrate 20, and the charged fine particles 22 fall on the surface of the substrate 20 due to a potential difference.
[0027] 次に，図 4の工程では，表面に複数の突起が形成された第 1の基板 10を上下反対 にして，多数の触媒材料の微粒子 22を担持した第 2の基板 20に対向させ，突起 12 の先端を微粒子 22に接触させて，突起先端に微粒子 22を付着させる。その結果， 図 5に示したように，第 1の基板 10の突起 12の先端に 1個の微粒子 22が付着した状 態になる。 Next, in the process of FIG. 4, the first substrate 10 having a plurality of protrusions formed on the surface is turned upside down so as to face the second substrate 20 carrying a large number of fine particles 22 of catalyst material. Then, the tip of the protrusion 12 is brought into contact with the fine particle 22 to attach the fine particle 22 to the tip of the protrusion. As a result, as shown in FIG. 5, one particle 22 is attached to the tip of the protrusion 12 of the first substrate 10.
[0028] 図 4の工程では，突起 12の先端を微粒子 22に接触させた状態で，例えば 300°C 程度に加熱することで，より効率的に突起先端に微粒子を付着させることができる。こ の加熱温度は，鉄などの触媒金属の融点よりはかなり低いが，加熱により金属が付 着しやすくなる。  In the step of FIG. 4, the fine particles can be more efficiently attached to the tips of the protrusions by heating to, for example, about 300 ° C. while the tips of the protrusions 12 are in contact with the fine particles 22. This heating temperature is considerably lower than the melting point of catalytic metals such as iron, but the metal is easily attached by heating.
[0029] 図 3, 4では，微粒子 22が隙間なく基板 20の表面に担持されているが，ある程度微 粒子 22間に隙間があったほうが，より効果的に，図 4の付着工程で突起 12の先端に 1個の微粒子 22を分離して付着させることができる。前述したとおり，触媒金属の微 粒子 22の粒径を所望の値にそろえており，そのような制御された粒径の触媒金属微 粒子 22を利用することで，直径もそろったカーボンナノチューブを成長させることが できる。したがって，突起先端にそれぞれ単一の微粒子 22を付着させることが望まし い。 In FIGS. 3 and 4, the fine particles 22 are supported on the surface of the substrate 20 without gaps. However, if there are gaps between the fine particles 22 to some extent, the projection 12 is more effective in the adhesion process of FIG. One fine particle 22 can be separated and attached to the tip of the substrate. As described above, the particle size of the catalyst metal fine particles 22 is adjusted to a desired value, and by using the catalyst metal fine particles 22 having such a controlled particle size, carbon nanotubes having a uniform diameter are grown. To let it can. Therefore, it is desirable to attach a single particle 22 to the tip of each protrusion.
[0030] 次に，図 6の工程では，第 1の基板を熱 CVD装置のチャンバ一内に導入し，基板 を約 600°Cに加熱しながら，アルゴン (Ar) ,アセチレン（C2H2) ,水素（H2)の混合 ガス（比率 90 : 10 : 1000)で，圧力 0. l〜lKPaの雰囲気内にて，触媒金属微粒子 2 2にカーボンナノチューブ CNTを成長させる。カーボンナノチューブ CNTは，微粒 子 22の粒径に対応した直径で成長開始し，その先端は隣接する突起表面に達する 。上記の CVD成長時間を所定時間，例えば 30分間に設定することで，カーボンナノ チューブ CNTの長さを制御することができ，触媒金属微粒子 22から隣接する突起 2 2に至る中空に孤立したカーボンナノチューブ CNTを成長させることができる。  Next, in the process of FIG. 6, the first substrate is introduced into the chamber of the thermal CVD apparatus, and while the substrate is heated to about 600 ° C., argon (Ar), acetylene (C2H2), hydrogen Carbon nanotubes CNT are grown on the catalytic metal fine particles 22 in an atmosphere of 0.1 to lKPa in a mixed gas of (H2) (ratio 90: 10: 1000). Carbon nanotubes CNT start growing at a diameter corresponding to the particle size of the fine particles 22, and the tip reaches the surface of the adjacent protrusion. By setting the above CVD growth time to a predetermined time, for example, 30 minutes, the length of the carbon nanotube CNT can be controlled, and the carbon nanotube isolated in the hollow from the catalytic metal fine particle 22 to the adjacent protrusion 22 CNT can be grown.
[0031] 図 7は，上記の CVD装置の概略構成図である。この装置は，チャンバ一 50内にス テージ 52と，ホットフィラメントからなる加熱手段 54とが設けられている。ホットフィラメ ント 54には電圧 56が印加され発熱し，ステージ 52上に載置された第 1の基板の表面 を加熱する。そして，チャンバ一 50内には，成長ガスとしてアルゴン (Ar) ,ァセチレ ン（C2H2) ,水素（H2)の混合ガス（比率 90 : 10 : 1000) 58が導入され，内部は圧力 0. l〜lKPaに維持される。ホットフィラメントの加熱により，第 1の基板 10の表面は 6 00°C程度に加熱される。それにより，触媒金属微粒子 22からカーボンナノチューブ CNTが成長する。  FIG. 7 is a schematic configuration diagram of the above CVD apparatus. In this apparatus, a stage 52 and a heating means 54 made of hot filament are provided in a chamber 50. A voltage 56 is applied to the hot filament 54 to generate heat, and the surface of the first substrate placed on the stage 52 is heated. Then, a mixed gas of argon (Ar), acetylene (C2H2), and hydrogen (H2) (ratio 90: 10: 1000) 58 is introduced into the chamber 50 as the growth gas. maintained at lKPa. By heating the hot filament, the surface of the first substrate 10 is heated to about 600 ° C. As a result, carbon nanotube CNTs grow from the catalytic metal particles 22.
[0032] 本発明者らによると，鉄の微粒子 22の径を 0. 5〜4nm程度にそろえることで，直径 l〜4nm程度で 1層または 2層のカーボンナノチューブを成長することができた。した がって，先端 12に単一の鉄の微粒子 22を付着させることで，直径のそろったそして 層数のそろったカーボンナノチューブを孤立して生成することができる。  According to the present inventors, by adjusting the diameter of the iron fine particles 22 to about 0.5 to 4 nm, it was possible to grow one or two-layer carbon nanotubes with a diameter of about 1 to 4 nm. Therefore, by attaching a single iron fine particle 22 to the tip 12, carbon nanotubes having a uniform diameter and a uniform number of layers can be generated in isolation.
[0033] [第 2の実施の形態]  [0033] [Second Embodiment]
第 1の実施の形態では，触媒材料として遷移金属の鉄，コバルト，ニッケルを利用し た。第 2の実施の形態では，これらの触媒金属と， Ti, Al, Ta, TIN, Ti02のいずれ かの金属とを混合したものを使用する。そのために，図 3で示したターゲット 32を，上 記の混合金属材料に代える。これにより，同様の製法によって，第 2の基板 20表面に 混合金属の微粒子 22を担持させることができる。それ以外の工程は，第 1の実施の 形態と同じである。 In the first embodiment, transition metals such as iron, cobalt, and nickel were used as catalyst materials. In the second embodiment, a mixture of these catalyst metals and any one of Ti, Al, Ta, TIN, and Ti02 is used. Therefore, the target 32 shown in Fig. 3 is replaced with the above mixed metal material. Thus, the mixed metal fine particles 22 can be supported on the surface of the second substrate 20 by the same manufacturing method. Other processes are the same as those in the first implementation. The form is the same.
[0034] 具体例としては，図 3にて，コノ レト 80%,チタン 20%の混合基板をターゲット 32に してレーザーアブレーシヨンすることで，両金属が混合した微粒子が生成される。  [0034] As a specific example, in FIG. 3, fine particles mixed with both metals are generated by laser ablation using a mixed substrate of 80% coronate and 20% titanium as the target 32.
[0035] [第 3の実施の形態]  [0035] [Third embodiment]
第 3の実施の形態では，図 1に示した第 1の基板 10の針状の突起 12の表面にあら かじめスパッタ法により Ti, Al, Ta, TiN, Ti02のいずれかの金属膜を lnm程度の 膜厚に形成する。そして，図 2, 4, 5の手順で突起 12にコバルトなどの触媒金属微 粒子 22を付着させ，熱 CVD法またはホットフィラメント CVD法により，カーボンナノチ ユーブを成長する。  In the third embodiment, a metal film of Ti, Al, Ta, TiN, or Ti02 is deposited on the surface of the needle-like protrusion 12 of the first substrate 10 shown in FIG. It is formed to a film thickness of about. Then, catalytic metal fine particles 22 such as cobalt are attached to the protrusions 12 according to the procedures shown in FIGS. 2, 4, and 5, and carbon nanotubes are grown by thermal CVD or hot filament CVD.
[0036] 図 8は，第 3の実施の形態により生成されたカーボンナノチューブ CNTを示す図で ある。針状の突起 12の表面にチタン膜 12が形成され，その上に付着されたコバルト 微粒子 22にカーボンナノチューブ CNTが成長している。このカーボンナノチューブ の化学気相成長では，基板を例えば 650°Cに加熱し，アルゴン，エタノールなどのァ ルコール，水素の混合ガスを導入し，圧力 0. lKPaに維持して，約 40分間保持する  FIG. 8 is a diagram showing the carbon nanotube CNT generated by the third embodiment. A titanium film 12 is formed on the surface of the needle-like protrusion 12, and carbon nanotubes CNT grow on cobalt fine particles 22 attached on the titanium film 12. In this chemical vapor deposition of carbon nanotubes, the substrate is heated to, for example, 650 ° C, a mixed gas of alcohol and hydrogen such as argon and ethanol is introduced, maintained at a pressure of 0.1 KPa, and held for about 40 minutes.
[0037] 上記のようにチタン膜 12をあら力じめ形成しておくことで，成長するカーボンナノチ ユーブ CNTはチタン膜 12との間に低抵抗のォーミックコンタクトを形成する。同様に ,成長するカーボンナノチューブ CNTの先端もチタン膜との間に低抵抗のォーミック コンタクトを形成する。この点については，本発明者らの論文（Japanese Journal of Ap plied Physics Vol. 43, No. 4B, 2004, As the titanium film 12 is preliminarily formed as described above, the growing carbon nanotube CNT forms an ohmic contact with low resistance between the titanium film 12. Similarly, the tip of the growing carbon nanotube CNT also forms a low-resistance ohmic contact with the titanium film. Regarding this point, our paper (Japanese Journal of Applied Physics Vol. 43, No. 4B, 2004,
pp.1856-1859)に詳述されている。  pp.1856-1859).
[0038] 上記のコバルト微粒子は，他の遷移金属の微粒子，遷移金属と Ti, Al, Ta, TiN, Ti02( V、ずれかの金属との混合物の微粒子であってもよ!、。  [0038] The cobalt fine particles may be fine particles of other transition metals, fine particles of a mixture of transition metal and Ti, Al, Ta, TiN, Ti02 (V, any metal!
[0039] [第 4の実施の形態]  [0039] [Fourth embodiment]
上記第 1〜第 3の実施の形態では，カーボンナノチューブの生成方法を示した。第 4の実施の形態では，カーボンナノチューブではなく， III V属の化合物半導体であ る細線物質の生成方法である。  In the first to third embodiments, the carbon nanotube generation method has been described. In the fourth embodiment, it is a method for producing a thin wire material that is not a carbon nanotube but a IIIV compound semiconductor.
[0040] 図 1にて針状の突起 12を有する第 1の基板 10を準備する。そして，図 2にて，第 2 の基板 20の表面に，触媒金属，例えば金の微粒子 22を担持させる。そして，図 4, 図 5と同様にして，第 1の基板 10の突起 12の先端に金の微粒子 22を付着させる。そ の後，第 1の基板を MOCVD (有機金属化学気相成長)装置内に搬入し， III— V属 の金属ガス雰囲気中で触媒微粒子 22に III V属の化合物半導体である細線物質を 成長させる。この細線物質は，図 6に示したカーボンナノチューブ CNTと同様に，触 媒微粒子 22から成長し，隣接する突起 12の表面に達する細いロッド状の物質となる In FIG. 1, a first substrate 10 having needle-like protrusions 12 is prepared. And in Fig. 2, the second A catalyst metal, for example, gold fine particles 22 is supported on the surface of the substrate 20. 4 and 5, gold fine particles 22 are attached to the tips of the protrusions 12 of the first substrate 10. After that, the first substrate is loaded into the MOCVD (Metal Organic Chemical Vapor Deposition) equipment, and the fine wire material, III-V compound semiconductor, is grown on the catalyst particles 22 in the III-V metal gas atmosphere. Let Similar to the carbon nanotube CNT shown in Fig. 6, this fine wire material grows from catalyst fine particles 22 and becomes a thin rod-like material that reaches the surface of the adjacent protrusion 12.
[0041] [第 5の実施の形態] [0041] [Fifth embodiment]
図 9は，第 5の実施の形態の生成工程を示す断面図である。この方法では，工程 (a )に示すとおり，第 1の基板 10の表面に，前述の方法により触媒材料の微粒子 22を 生成する。そして，工程 (b)に示すとおり，その微粒子 22をマスクにして，第 1の基板 10の表面を例えばイオンミリング法によりエッチングして，針状の突起 12を形成する 。その結果，基板 10の表面の突起 12の先端に触媒材料の微粒子 22を付着した状 態を形成することができる。つまり，図 5と同じ状態である。  FIG. 9 is a cross-sectional view showing the generation process of the fifth embodiment. In this method, as shown in step (a), fine particles 22 of the catalyst material are generated on the surface of the first substrate 10 by the method described above. Then, as shown in step (b), using the fine particles 22 as a mask, the surface of the first substrate 10 is etched by, for example, ion milling to form needle-like protrusions 12. As a result, it is possible to form a state in which fine particles 22 of the catalyst material adhere to the tips of the protrusions 12 on the surface of the substrate 10. In other words, this is the same state as in Fig. 5.
[0042] その後は，図 6, 7で説明した CVD方法により，触媒材料の微粒子 22にカーボンナ ノチューブなどを孤立して成長させる。  [0042] Thereafter, carbon nanotubes and the like are grown independently on the fine particles 22 of the catalyst material by the CVD method described in FIGS.
[0043] 第 5の実施の形態によれば，複数の突起の先端に触媒微粒子を孤立して付着させ た構造を容易に形成することができる。  [0043] According to the fifth embodiment, it is possible to easily form a structure in which catalyst fine particles are isolated and attached to the tips of a plurality of protrusions.
[0044] 以上の第 1〜第 5の実施の形態における化学気相成長の成長ガスは，アセチレン， アルコール以外にも炭素含有液体を気化させたガスであってもよく，水素 H2以外に も窒素 N2であってもよく，さらに，アルゴン Ar以外にもヘリウム Heであっても良い。そ して，成長ガスは，炭化水素，アルコールなどの炭素含有液体を気化させたガスを単 独で使用してもよく，または水素，窒素，アルゴン，ヘリウムの少なくとも 1つと混合し た混合ガスを使用してもょ 、。  [0044] The growth gas for chemical vapor deposition in the first to fifth embodiments described above may be a gas obtained by vaporizing a carbon-containing liquid in addition to acetylene and alcohol. In addition to hydrogen H2, nitrogen may also be used. N2 may be used, and in addition to argon Ar, helium He may be used. As the growth gas, a gas obtained by vaporizing a carbon-containing liquid such as hydrocarbon or alcohol may be used alone, or a mixed gas mixed with at least one of hydrogen, nitrogen, argon, and helium may be used. You can use it.
[0045] 以上説明したとおり，本実施の形態によれば，空中にぶら下がった孤立したカーボ ンナノチューブや細線物質を再現性良く生成することができる。したがって，所望の 特性を有するカーボンナノチューブの量産化に寄与することができる。 [0045] As described above, according to the present embodiment, it is possible to generate an isolated carbon nanotube or fine wire substance hanging in the air with good reproducibility. Therefore, it can contribute to mass production of carbon nanotubes with desired characteristics.
産業上の利用可能性 本発明によれば，孤立したカーボンナノチューブなどの細線物質を再現性よく生成 することができる。 Industrial applicability According to the present invention, it is possible to generate a fine wire substance such as an isolated carbon nanotube with good reproducibility.

Claims

請求の範囲 The scope of the claims
[1] 表面に複数の突起が形成された第 1の基板を準備する第 1の工程と，  [1] a first step of preparing a first substrate having a plurality of protrusions formed on the surface;
第 2の基板上に触媒材料カゝらなる微粒子を複数個生成する第 2の工程と， 前記第 1の基板に形成された複数の突起を前記第 2の基板上に形成された触媒材 料の微粒子に接触させて，当該複数の突起に触媒材料の微粒子を付着させる第 3 の工程と，  A second step of generating a plurality of fine particles comprising a catalyst material on a second substrate; and a catalyst material having a plurality of protrusions formed on the first substrate formed on the second substrate. A third step of bringing the catalyst material fine particles into contact with the plurality of protrusions in contact with the fine particles;
前記第 1の基板を炭素含有ガス雰囲気中に置いて前記触媒材料の微粒子にカー ボンナノチューブを成長させる第 4の工程とを有するカーボンナノチューブの生成方 法。  And a fourth step of growing the carbon nanotubes on the fine particles of the catalyst material by placing the first substrate in a carbon-containing gas atmosphere.
[2] 請求項 1において，  [2] In claim 1,
前記触媒材料が，少なくともコバルト，鉄，ニッケルを含む遷移金属であるカーボン ナノチューブの生成方法。  A method for producing carbon nanotubes, wherein the catalyst material is a transition metal containing at least cobalt, iron, and nickel.
[3] 請求項 1において， [3] In claim 1,
前記触媒材料が，少なくともコバルト，鉄，ニッケルを含む遷移金属と， Ti, Al, Ta , TiN, TiOのいずれかの金属とを合金化したものであるカーボンナノチューブの生  The catalyst material is a carbon nanotube produced by alloying a transition metal containing at least cobalt, iron, and nickel with any one of Ti, Al, Ta, TiN, and TiO.
2  2
成方法。  How to complete.
[4] 請求項 2または 3において，  [4] In claim 2 or 3,
前記第 3の工程で，前記第 1の基板の突起を前記第 2の基板の触媒材料の微粒子 に接触した状態で，所定の温度に加熱して前記突起に触媒材料の微粒子を付着さ せるカーボンナノチューブの生成方法。  In the third step, the carbon that adheres the fine particles of the catalyst material to the protrusions by heating to a predetermined temperature in a state where the protrusions of the first substrate are in contact with the fine particles of the catalyst material of the second substrate. Nanotube production method.
[5] 請求項 1において， [5] In claim 1,
前記第 3の工程の前に，前記第 1の工程で準備した第 1の基板の複数の突起表面 に， Ti, Al, Ta, TiN, TiOのいずれかの金属層を形成する第 5の工程を有する力  Before the third step, a fifth step of forming a metal layer of any one of Ti, Al, Ta, TiN, and TiO on the surface of the plurality of protrusions of the first substrate prepared in the first step Having power
2  2
一ボンナノチューブの生成方法。  A method for producing single-bonn nanotubes.
[6] 請求項 1において，  [6] In claim 1,
前記遷移材料の微粒子が， 0. 5〜： LOnmの径を有する遷移金属微粒子であり，前 記第 4の工程で成長するカーボンナノチューブが l〜4nmの直径で単層または 2層 構造であるカーボンナノチューブの生成方法。 The transition material fine particles are transition metal fine particles having a diameter of 0.5 to: LOnm, and the carbon nanotubes grown in the fourth step are carbon with a diameter of 1 to 4 nm and a single-layer or double-layer structure. Nanotube production method.
[7] 請求項 1において， [7] In claim 1,
前記第 2の工程では，前記触媒材料にエネルギービームを照射して気化させ，気 化した触媒材料を微粒子化させ，当該微粒子のうち所定の径の微粒子を選択して， 前記第 2の基板上に積もらせるカーボンナノチューブの生成方法。  In the second step, the catalyst material is irradiated with an energy beam to vaporize, the vaporized catalyst material is atomized, and fine particles having a predetermined diameter are selected from the fine particles, and the second substrate is selected. A method for producing carbon nanotubes to be stacked.
[8] 請求項 1において， [8] In claim 1,
前記第 4の工程は，前記炭素含有ガスが，炭化水素もしくはアルコールなどの炭素 含有液体を気化させたガスであり，当該炭素含有ガス単独あるいはそれと H , N , A  In the fourth step, the carbon-containing gas is a gas obtained by vaporizing a carbon-containing liquid such as hydrocarbon or alcohol, and the carbon-containing gas alone or H, N, A
2 2 r, Heの少なくとも一つと混合した混合ガスである化学気相成長法であるカーボンナ ノチューブの生成方法。  A method for producing carbon nanotubes, which is chemical vapor deposition, which is a mixed gas mixed with at least one of 2 2 r and He.
[9] 表面に複数の突起が形成された第 1の基板を準備する第 1の工程と， [9] a first step of preparing a first substrate having a plurality of protrusions formed on the surface;
第 2の基板上に触媒材料カゝらなる微粒子を複数個生成する第 2の工程と， 前記第 1の基板に形成された複数の突起を前記第 2の基板上に形成された触媒材 料の微粒子に接触させて，当該複数の突起に触媒材料の微粒子を付着させる第 3 の工程と，  A second step of generating a plurality of fine particles comprising a catalyst material on a second substrate; and a catalyst material having a plurality of protrusions formed on the first substrate formed on the second substrate. A third step of bringing the catalyst material fine particles into contact with the plurality of protrusions in contact with the fine particles;
前記第 1の基板を成長ガス雰囲気中に置いて前記触媒材料の微粒子に細線物質 を成長させる第 4の工程とを有する細線物質の生成方法。  And a fourth step of growing the fine wire substance on the fine particles of the catalyst material by placing the first substrate in a growth gas atmosphere.
[10] 請求項 9において，前記触媒材料が Auであり，前記細線物質力 GaAs, InP, InA sを含む III V属の化合物半導体である細線物質の生成方法。 10. The method for producing a fine wire substance according to claim 9, wherein the catalyst material is Au and the fine wire substance force GaAs, InP, InAs is included in a group IIIV compound semiconductor.
[11] 請求項 10において，前記第 4の工程が，前記 III V属の金属ガスを成長ガスとして 使用する有機金属化学気相成長法である細線物質の生成方法。 [11] The method of producing a thin wire substance according to claim 10, wherein the fourth step is a metal organic chemical vapor deposition method using the group IIIV metal gas as a growth gas.
[12] 基板上に触媒材料カゝらなる微粒子を複数個生成する第 1の工程と， [12] a first step of generating a plurality of fine particles comprising a catalyst material on a substrate;
前記基板の表面を前記複数の微粒子をマスクにしてエッチングして，先端に前記 微粒子が付着した複数の突起を形成する第 2の工程と，  A second step of etching the surface of the substrate using the plurality of fine particles as a mask to form a plurality of protrusions having the fine particles attached to the tip;
前記基板を成長ガス雰囲気中に置 ヽて前記触媒材料の微粒子に細線物質を成長 させる第 3の工程とを有する細線物質の生成方法。  And a third step of growing the fine line substance on the fine particles of the catalyst material by placing the substrate in a growth gas atmosphere.
[13] 請求項 12において，前記触媒材料が少なくともコバルト，鉄，ニッケルを含む遷移 金属であり，前記細線物質がカーボンナノチューブである細線物質の生成方法。 13. The method for producing a fine line substance according to claim 12, wherein the catalyst material is a transition metal containing at least cobalt, iron, and nickel, and the fine line substance is a carbon nanotube.
PCT/JP2006/305866 2006-03-23 2006-03-23 Process for producing carbon nanotube WO2007108132A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009173497A (en) * 2008-01-25 2009-08-06 Mie Univ Carbon nanotube synthetic method using paracrystalline catalyst

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001020071A (en) * 1999-06-11 2001-01-23 Cheol Jin Lee Synthesis of carbon nanotube
JP2001081564A (en) * 1999-07-27 2001-03-27 Cheol Jin Lee Chemical vapor deposition system and method for synthesizing carbon nanotube using the same
JP2004051432A (en) * 2002-07-19 2004-02-19 Fujitsu Ltd Substrate for manufacturing carbon nanotube and method of manufacturing carbon nanotube using the same
JP2004182537A (en) * 2002-12-04 2004-07-02 Mie Tlo Co Ltd Method of forming arranged structure of nanocarbon material
JP2004241295A (en) * 2003-02-07 2004-08-26 Hitachi Zosen Corp Electrode material for electron emission element using carbon nanotube and its manufacturing method
JP2005246507A (en) * 2004-03-02 2005-09-15 Pioneer Electronic Corp Device for arranging material to tip
JP2005272171A (en) * 2004-03-23 2005-10-06 Nippon Telegr & Teleph Corp <Ntt> Method for manufacturing carbon nanotube

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001020071A (en) * 1999-06-11 2001-01-23 Cheol Jin Lee Synthesis of carbon nanotube
JP2001081564A (en) * 1999-07-27 2001-03-27 Cheol Jin Lee Chemical vapor deposition system and method for synthesizing carbon nanotube using the same
JP2004051432A (en) * 2002-07-19 2004-02-19 Fujitsu Ltd Substrate for manufacturing carbon nanotube and method of manufacturing carbon nanotube using the same
JP2004182537A (en) * 2002-12-04 2004-07-02 Mie Tlo Co Ltd Method of forming arranged structure of nanocarbon material
JP2004241295A (en) * 2003-02-07 2004-08-26 Hitachi Zosen Corp Electrode material for electron emission element using carbon nanotube and its manufacturing method
JP2005246507A (en) * 2004-03-02 2005-09-15 Pioneer Electronic Corp Device for arranging material to tip
JP2005272171A (en) * 2004-03-23 2005-10-06 Nippon Telegr & Teleph Corp <Ntt> Method for manufacturing carbon nanotube

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SATO S. ET AL.: "Growth of diameter-controlled carbon nanotubes using monodisperse nickel nanoparticles obtained with a differential mobility analyzer", CHEMICAL PHYSICS LETTERS, vol. 382, 2003, pages 361 - 366, XP003001225 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009173497A (en) * 2008-01-25 2009-08-06 Mie Univ Carbon nanotube synthetic method using paracrystalline catalyst

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