JP5052954B2 - CNT growth method - Google Patents

Description

  The present invention relates to a CNT (carbon nanotube) growth method.

  In the technical field of semiconductor devices, a technique of growing CNTs on the bottom surface of a hole such as a fine via hole and using it as wiring (for example, see Patent Document 1). When applying a plurality of CNTs as a bundle when applying the CNTs to a semiconductor device, the density of the CNTs greatly affects the characteristics of the semiconductor device. Therefore, it is important to improve the CNT density in the CNT bundle, but there is still no satisfactory technology at present.

  Conventionally, when a CNT growth catalyst is attached to a CNT growth substrate, a catalyst metal film is formed by EB vapor deposition or sputtering, or a solution or dispersion obtained by dissolving or dispersing the catalyst metal in a solvent is used as the substrate. A method is known in which a film is formed by coating on a substrate and drying, or by applying a dispersion obtained by dispersing a catalyst metal produced as fine particles in a solvent on a substrate and drying the film. In the film forming method such as the EB vapor deposition method or the sputtering method, the catalyst metal spreads in a film shape on the substrate and is then formed into fine particles by a heating process before or during CNT growth. In this case, there is a problem that the diameter of the catalyst metal fine particles increases under the influence of various conditions such as the buffer layer, process conditions, and catalyst film thickness. For example, the catalyst metal fine particles aggregate due to the substrate heat treatment when controlling the CNT growth, resulting in an increase in particle size and a decrease in density, resulting in a decrease in CNT density after growth. There is.

When a CNT bundle is used as a via wiring in a semiconductor device, the density of the CNTs greatly affects the specific resistance, so that a high density is desired. However, the density of CNTs obtained by the conventional CNT growth method is about ¹⁰ 10 to ¹¹ pieces / cm ² , and the volume filling rate is as small as about 1 to 10%. It is desired.

In addition, as a method for forming an inter-element interconnect that connects a plurality of micro-elements formed on a substrate, a method is known in which a CNT is grown between catalyst fine particles made of an oxide of a transition metal to form an interconnect. (See, for example, Patent Document 2). In this case, the transition metal oxide fine particles are reduced to metal by heating on the silicon substrate to exhibit a catalytic action, and the CNT grows along the substrate surface in a self-organized manner. It cannot be used as a method of growing in Japan.
JP 2005-285821 A (Claims etc.) JP 2003-158093 A (Claims etc.)

  An object of the present invention is to solve the above-described problems of the prior art, and to provide a CNT growth method capable of vertically growing CNTs in a bundle and at a high density.

CNT growth method of the present invention, the substrate you have a oxide layer of catalytic metal used as a catalyst layer for CNT growth, supplying a CNT growth process gas to the substrate, growing a CNT on the substrate In the CNT growth method, the catalyst metal oxide layer forms catalyst metal fine particles using a coaxial vacuum arc deposition source and oxidizes the formed catalyst metal fine particles in an oxidizing atmosphere to oxidize the catalyst metal. obtaining things microparticles, the obtained oxide particles were formed by adhering to the substrate surface, during the CNT growth process, the oxide particles of the catalyst metal from the process gas is reduced to catalyst metal fine particles, the It is characterized by growing CNTs on fine particles of catalytic metal.

Before the formation of Kisawa medium metal oxide layer, characterized Rukoto that Nessu substrates pressure.

  The oxidizing atmosphere is a gas atmosphere selected from oxygen gas, water vapor, carbon monoxide gas, and carbon dioxide gas.

  According to the present invention, there is an effect that it is possible to provide CNTs that are vertically grown in a bundle and improved in density.

  Embodiments of the present invention will be described below.

  The substrate for CNT growth used in the present invention is a catalyst film-forming process at the time of its production, and an oxide of a catalyst metal, for example, at least one metal selected from Co, Ni and Fe, or at least one of these metals Catalyst metal oxide microparticles made of an alloy containing are formed. As this film forming step, for example, an existing method such as a sputtering method, an EB vapor deposition method, a laser ablation method, and a method using a coaxial vacuum arc vapor deposition source can be used. Among these methods, it is preferable to use a sputtering method or a coaxial vacuum arc evaporation source method that can form a catalyst metal oxide with nanometer-order fine particles. In this case, even if the catalytic metal oxide fine particle layer is formed by the formation process of the catalytic metal oxide fine particle layer in the oxidizing atmosphere, the catalytic metal fine particle layer is formed in the non-oxidizing atmosphere. You may form by the formation process of the fine particle layer of a catalyst metal oxide in a process and subsequent oxidizing atmosphere.

  As in the above sputtering method, in a method using a normal gas, if an oxidizing gas such as oxygen gas, air, water vapor, ozone, nitrogen dioxide or the like is mixed in a known sputtering gas, it is formed on the substrate. Since catalyst metal oxide fine particles can be formed, it is preferable. In the case of the sputtering method, the catalyst metal oxide fine particles may be formed by first performing sputtering in a non-oxidizing atmosphere to form a catalyst metal, and then performing oxidation.

  In the case of a film forming method that does not normally use a gas, such as a coaxial vacuum arc evaporation source method, it is necessary to form a film in an oxidizing atmosphere such as oxygen gas in the present invention. At this time, by forming the film while heating the substrate to 200 ° C. or more, the catalytic metal oxide fine particles can be formed more effectively.

  Hereinafter, a structural example of a vacuum chamber provided with a coaxial vacuum arc deposition source and a method of forming a catalytic metal oxide fine particle layer using this deposition source will be described.

  In the present invention, as a coaxial vacuum arc vapor deposition source, for example, a cylindrical trigger electrode and a columnar or cylindrical cathode electrode having at least a tip formed of a catalytic metal material for vapor deposition include a cylindrical insulator. It is possible to use a vapor deposition source in which a cylindrical anode electrode is coaxially arranged around the cathode electrode and spaced apart from the cathode electrode. The coaxial vacuum arc deposition source is driven, and a catalytic metal material constituting the cathode electrode is deposited on a substrate placed in a vacuum chamber in an oxidizing atmosphere to react with oxygen atoms in the atmosphere. Thus, a fine particle layer of the catalytic metal oxide is formed. A vacuum chamber equipped with this vapor deposition source will be described with reference to FIG.

  A substrate stage 12 is horizontally disposed below the cylindrical vacuum chamber 11. The vacuum chamber 11 is provided with a rotation mechanism having a rotation driving means 13 such as a motor at the center of the back surface of the substrate stage so that the substrate stage 12 can be rotated in a horizontal plane.

  A heating means 14 such as a heater is provided on the surface opposite to the substrate placement side of the substrate stage so that the substrate stage 12 on which the substrate S is placed can be heated so that the substrate can be heated to a predetermined temperature if desired. It is configured.

  Above the vacuum chamber 11, a coaxial vacuum arc vapor deposition source 15, which will be described later, is disposed so as to face the substrate stage 12. This coaxial type vacuum arc vapor deposition source 15 is disposed so as to face the main surface of the substrate S placed on the substrate stage 12 with the tip of the cathode electrode 15a facing the substrate stage 12, and from the cathode electrode 15a. The generated fine particles of the catalytic metal are arranged so as to fall on the main surface of the substrate S and be irradiated uniformly. Thus, the catalytic metal fine particles can fly from the upper side to the lower side of the vacuum chamber 11 and be deposited on the substrate S.

An oxidizing gas introduction system 16 and a vacuum exhaust system 17 are connected to the wall surface of the vacuum chamber 11. The oxidizing gas introduction system 16 is an introduction system for oxygen gas or the like for making the inside of the vacuum chamber 11 an oxidizing atmosphere. In this gas introduction system, the valve 16a, the mass flow controller 16b, the valve 16c, and the gas cylinder 16d are connected by metal piping in this order. Further, the evacuation system 17 includes a conductance valve 17a, a turbo molecular pump 17b, a valve 17c, and a rotary pump 17d connected in this order by a metal vacuum pipe, and the inside of the vacuum chamber 11 is preferably 10 ⁻⁴ Pa or less. It can be evacuated.

  As shown in FIG. 1, a coaxial vacuum arc deposition source 15 provided in a vacuum chamber 11 has a cylindrical shape in which one end is closed and the other end facing the substrate stage 12 is open, and is made of a catalytic metal. Alternatively, a cylindrical cathode electrode 15a, a cylindrical anode electrode 15b made of stainless steel, a cylindrical trigger electrode (for example, a ring-shaped trigger electrode) 15c made of stainless steel, and a cathode electrode 15d and a trigger electrode 15c, and a disc-shaped or cylindrical insulator (hereinafter also referred to as a hat-type insulator) 15d provided to separate the two from each other, and these are attached coaxially. ing. The cathode electrode 15 a is provided to face the substrate stage 12. Although not shown, the three components of the cathode electrode 15a, the insulator 15d, and the trigger electrode 15c are closely attached with screws or the like and attached coaxially. Although not shown, the anode electrode 15 b is attached to a vacuum flange with a support, and this vacuum flange is attached to the upper surface of the vacuum chamber 11. The cathode electrode 15a is coaxially provided inside the anode electrode 15b and separated from the wall surface of the anode electrode by a certain distance. The cathode electrode 15a only needs to be formed of a catalyst metal at least at the tip (corresponding to the end of the anode 15b on the opening side).

  The trigger electrode 15c is attached with an insulator 15d made of alumina or the like sandwiched between the target material or the cathode electrode 15a. The insulator 15d may be attached to insulate the cathode electrode 15a from the trigger electrode 15c, and the trigger electrode 15c may be attached to the cathode electrode 15a via an insulator. It is preferable that the anode electrode 15b, the cathode electrode 15a, and the trigger electrode 15c are electrically insulated by an insulator 15d and an insulator. The insulator 15d and the insulator may be configured integrally or separately.

  A trigger power source 15e composed of a pulse transformer is connected between the cathode electrode 15a and the trigger electrode 15c, and an arc power source 15f is connected between the cathode electrode 15a and the anode electrode 15b. The arc power source 15f includes a DC voltage source 15g and a capacitor unit 15h. Both ends of the capacitor unit 15h are connected to the cathode electrode 15a and the anode electrode 15b, respectively. The capacitor unit 15h and the DC voltage source 15g are connected in parallel. Has been.

  The capacitor unit 15h is connected to one or a plurality of capacitors (one capacitor is illustrated in FIG. 1), and one capacitor thereof is, for example, 2200 μF (withstand voltage 160V), The DC voltage source 15g can be charged at any time. The trigger power supply 15c transforms a pulse voltage of μs with an input of 200V by about 17 times, and outputs 3.4 kV (several μA) and polarity: plus. The arc power supply 15f has a DC voltage source 15g having a capacity of 100V and several A, and the capacitor unit 15h (for example, 8800 μF in the case of four capacitor units) is charged from this DC voltage source. Since this charging time takes about 1 second, the period when discharging is repeated at 8800 μF in this system is 1 Hz. The positive output terminal of the trigger power supply 15e is connected to the trigger electrode 15c, and the negative terminal is connected to the same potential as the negative output terminal of the DC voltage source 15g of the arc power supply 15f, and is connected to the cathode electrode 15a. The plus terminal of the DC voltage source 15g of the arc power supply 15f is grounded to the ground potential and connected to the anode electrode 15b. Both terminals of the capacitor unit 15h are connected between a plus terminal and a minus terminal of the DC voltage source 15g.

  Reference numeral 18 in FIG. 1 denotes a controller, which is connected to a trigger power supply 15e. When a signal is input to the trigger power supply 15e connected to the controller by turning on the switch of the controller, the controller supplies a high voltage. Is output. The controller 18 is preferably connected to a CPU (not shown) and configured to operate the controller by a signal (external signal) from the CPU.

  Next, a method for forming a fine particle layer of catalytic metal oxide on the main surface of the substrate S placed on the substrate stage 12 in the vacuum chamber 11 provided with the coaxial vacuum arc deposition source 15 shown in FIG. To do.

First, the substrate is set to a predetermined temperature (for example, 200 ° C. or higher, preferably 300 to 500 ° C.) by a heating means such as a heater, then valves 16a and 16c are opened, and a predetermined flow rate is set via the mass flow controller 16b. An oxidizing gas such as oxygen is introduced into the vacuum chamber 11 and the conductance valve 17a is adjusted to adjust the pressure in the vacuum chamber to a predetermined pressure (for example, 1 × 10 ^{−3 to} 1.0 Torr, preferably 1 × 10 ⁻² Torr).

  The DC voltage source 15g charges the capacitor unit 15h with 100V, sets the capacitance of the capacitor unit 15h to 8800 μF, and then outputs a pulse voltage from the trigger power supply 15e to the trigger electrode 15c (output: 3.4 kV), By applying a hat type insulator 15d between the cathode electrode 15a and the trigger electrode 15c, a trigger discharge (a creeping discharge on the surface of the hat type insulator) is generated between the cathode electrode 15a and the trigger electrode 15c. Electrons are generated from the joint between the cathode electrode 15a and the hat insulator 15d. Due to this trigger discharge, the electric charge stored in the capacitor unit 15h is vacuum arc discharged between the side surface of the cathode electrode 15a and the inner surface of the anode electrode 15b, and a large amount of arc current flows into the cathode electrode 15a. As a result, the catalytic metal material constituting the cathode electrode 15a is converted from a liquid phase to a gas phase, and plasma of this metal is further formed. Discharging is stopped by the discharge of the electric charge stored in the capacitor unit 15h. This trigger discharge is repeated a predetermined number of times, and an arc discharge is induced for each trigger discharge. The number of trigger discharges, and hence the number of arc discharges, can be performed by inputting a desired number of discharges to the controller 18.

  During the above-described arc discharge, fine particles (atomic ions, clusters, electrons, etc. that are turned into plasma) generated by melting of the catalytic metal material are formed. The fine particles are discharged into the vacuum chamber 11 from the opening (discharge port) of the anode electrode 15b, and the fine particles formed as described above are formed on the main surface of the substrate S disposed below the opening. Then, catalyst metal oxide fine particles formed by reaction with an oxidizing gas such as oxygen gas are adhered on the surface of the substrate S and agglomerated to form an oxide layer of the catalyst metal. The catalyst metal oxide layer adheres to the substrate with better adhesion than the EB deposition method, and the film thickness can be easily controlled.

  The metal fine particles are released as follows. Since a large amount of current flows through the cathode electrode 15a, a magnetic field is formed at the cathode electrode 15a, and electrons in the plasma generated at this time (the electrons fly from the cathode electrode 15a to the cylindrical inner surface of the anode electrode 15b) are self-formed. It receives Lorentz force by the magnetic field and flies forward. On the other hand, the metal ions of the cathode electrode material in the plasma fly forward so that the electrons fly and polarize as described above and are attracted to the forward electrons by Coulomb force, and fine particles are supplied onto the substrate S. Will be.

  In the above description, the length of the cable that is the wiring from the arc power source 15f to the coaxial vacuum arc deposition source 15 is set to about 1 m.

  Next, the substrate having the vapor deposition film obtained as described above is taken out from the vacuum chamber 11 and subjected to the CNT growth step. In this case, the configuration of the vacuum chamber 11 may be changed so that the CNT growth process can be performed in the same vacuum chamber 11, or the CNT growth may be performed in another chamber.

  CNT growth using the substrate on which the catalytic metal oxide fine particles obtained as described above are formed is performed by CVD such as known thermal CVD method, plasma CVD method, remote plasma CVD method, filament CVD method, etc. Can be carried out under known process conditions. In these methods, the substrate temperature is usually 400 ° C. or higher. Therefore, when the catalyst is in a metal state, the catalyst metal fine particles are aggregated during the CNT growth step, and the number of CNTs growing per unit area is reduced. On the other hand, the catalyst metal fine particles are oxidized. In this state, even when the temperature reaches the vicinity of the CNT growth temperature, the aggregation of the fine particles hardly occurs, and the growth can be started with the number of fine particles being large.

In the present invention, the fine particles are in an oxide state before CNT growth. However, the CNT growth atmosphere is usually a reducing atmosphere in which a decomposition gas of a source gas (process gas) that is a carbon atom-containing compound such as H ₂ , CO, or C ₂ H ₄ exists, so that the temperature of the substrate is increased. At the same time, the catalytic metal oxide is reduced to a catalytic metal state, and CNT growth is possible. Although the particle size is smaller than about 1 nm in the oxidized state, when reduced during the CNT growth process as described above, the particle size increases as it is reduced, and when the optimum particle size becomes about 1 to 3 nm, The growth of CNT begins, and the CNT grows suitably. Once the CNTs start to grow, the particles do not aggregate. As a result, CNT grows on a catalyst metal having an optimum particle diameter that does not progress agglomeration, so that CNTs having a uniform diameter and high density can be obtained.

  In the present invention, as described above, the catalytic metal oxide is reduced during the CNT growth process. However, when CNT growth is performed by a thermal CVD method using a gas having a weak reduction effect (for example, ethylene), In the case where CNT growth is performed by the CVD method by mixing an oxidant such as the above, it is necessary to perform CNT growth by mixing a reducing gas such as hydrogen.

  The remote plasma CVD method that performs CNT growth is a method in which a source gas (reactive gas) is decomposed into ionic species and radical species in the plasma, and the ionic species in the source gas obtained by this decomposition are removed to remove radical species. In this method, CNT growth is performed in a reducing atmosphere as a raw material. By irradiating the surface of the substrate on which the catalyst layer or the catalyst is formed with the radical species generated by decomposing the source gas used for CNT growth in plasma, CNTs can be efficiently grown at a low temperature. This radical species includes, for example, a hydrogen atom-containing gas (dilution gas) selected from a source gas such as hydrogen gas and ammonia and a carbon atom-containing gas that is a hydrocarbon gas or an alcohol gas in plasma. It is a radical obtained by decomposition. For example, hydrogen radicals and carbon radicals generated by decomposing a mixed gas of a hydrogen atom-containing gas and a carbon atom-containing gas in plasma. In this case, the source gas is decomposed in, for example, a plasma generated by a microwave or an RF power source, and it is particularly preferable to use a microwave that generates a large amount of radical species.

The CNT growth material that can be used is not particularly limited, and includes, for example, a combination of H ₂ and CO (for example, a flow rate ratio of 1: 1), H ₂ , CH _4, and C ₂ , including the source gas. Examples thereof include a combination with a saturated or unsaturated hydrocarbon such as H ₂ or an alcohol. In this case, the hydrocarbon may be one diluted with an inert gas such as N ₂ or Ar or He. Also, the conditions of the CNT growth process are not particularly limited, and normal growth process conditions may be used.

A preferred substrate that can be used in the present invention is not particularly limited, but for example, a substrate made of silicon such as Si (100), amorphous carbon, silica (SiO ₂ , quartz), SiC, sapphire (Al ₂ O ₃ ), or the like. Can be mentioned.

  Hereinafter, the present invention will be specifically described based on examples.

In this example, Co oxide fine particles are formed on the Si (100) substrate on which TiN is formed to a thickness of 20 nm using the coaxial vacuum arc evaporation source 15 shown in FIG. 1 provided with the cathode electrode 15a made of Co. did. That is, the valves 16a and 16c are opened, a predetermined flow rate of oxygen gas is introduced into the vacuum chamber 11 via the mass flow controller 16b, the conductance valve 17a is adjusted, and the pressure in the vacuum chamber 11 is set to 1 × 10 ⁻ Adjusted to a pressure of ³ Torr (1.33 × 10 ⁻¹ Pa) or 1 × 10 ⁻² Torr (1.33 Pa), and produced by reaction of Co and oxygen on the substrate S in this oxidizing atmosphere Co oxide fine particles were formed.

  The coaxial vacuum arc deposition source was driven as follows. That is, the DC voltage source 15g charges the capacitor unit 15h with 100V, sets the capacity of the capacitor unit 15h to 8800 μF, and then outputs a pulse voltage from the trigger power supply 15e to the trigger electrode 15c (output: 3.4 kV). ), A trigger discharge (a creeping discharge on the surface of the hat insulator) is generated between the cathode electrode 15a and the trigger electrode 15c by being applied between the cathode electrode 15a and the trigger electrode 15c via the hat insulator 15d. I let you. Electrons were generated from the joint between the cathode electrode 15a and the hat-type insulator 15d. Due to this trigger discharge, the electric charge stored in the capacitor unit 15h is vacuum arc discharged between the side surface of the cathode electrode 15a and the inner surface of the anode electrode 15b, and a large amount of arc current flows into the cathode electrode 15a. As a result, Co, which is the constituent metal material of the cathode electrode 15a, was converted from the liquid phase to the gas phase, and this Co plasma was formed. Discharging stopped due to the discharge of the charge stored in the capacitor unit 15h. This trigger discharge was repeated a predetermined number of times so that the thickness of the Co oxide fine particles became 20 nm.

  During the arc discharge described above, fine particles (atomic ions, clusters, electrons, etc. that are turned into plasma) generated by melting of Co are discharged into the vacuum chamber 11 from the opening (discharge port) of the anode electrode 15b, and the opening The substrate S placed in the downward direction is irradiated with the fine particles formed as described above, and the Co oxide fine particles are adhered and aggregated by reaction with oxygen gas on the surface of the substrate S. A Co oxide fine particle layer was formed. The length of the cable which is the wiring from the arc power source 15f to the coaxial vacuum arc deposition source 15 was set to about 1 m.

  When the appearance of the particle layer thus obtained was observed, it was found that when the pressure in the oxygen atmosphere was higher, the deposited Co became brown and Co was oxidized.

  CNTs were grown by remote plasma CVD using the substrate on which the Co oxide particle layer thus obtained was formed. As a remote plasma CVD apparatus, a quartz tube having an inner diameter of 50 mm in a vacuum chamber, having a gas supply port at one end and a gas discharge port at the other end, and in the vicinity of the gas discharge port The apparatus provided with the mesh-shaped shielding member produced with Mo was used.

From the gas supply port of the quartz tube, a mixed gas (CH ₂ CH ₂ : H ₂ = 5 sccm: 95 sccm) composed of ethylene gas and hydrogen gas is used as a reaction gas, 10.0 Torr (1.33 × 10 ³ Pa). The inside of the quartz tube is introduced with microwaves (output: 500 W) from the outside in the lateral direction of the quartz tube, and the mixed gas that has passed through the generated plasma is introduced from the gas outlet of the quartz tube. CNT is blown onto the substrate placed in the vacuum chamber using the gas from which the ion component in the gas has been removed by passing through the mesh portion of the shielding member provided in the vicinity of the gas outlet. Grew.

  The substrate temperature was kept constant at 550 ° C. by a heater.

As described above, a bundle of CNTs was grown in a via hole having a diameter of 5 μm in a direction perpendicular to the substrate. The CNTs grown vertically in the via holes are solidified by SOG spin coating and vacuum firing (process conditions: 1 × 10 ⁻³ Torr, 400 ° C., 30 minutes), and the surface is polished to obtain a CNT cross section. And density were measured. The diameter of CNT is about 5 nm in any via hole, and it was found by TEM observation that it is a 5-layer CNT.

When the CNT growth was performed in a vacuum instead of in an oxygen atmosphere, the density of CNTs was about 1 × 10 ¹¹ pieces / cm ² in the substrate on which the Co film was formed, but the oxygen atmosphere was 2 × 10 ^{− The} substrate formed in ³ Torr (2.66 × 10 ⁻¹ Pa) is formed in 5 × 10 ¹² pieces / cm ² and in an oxygen atmosphere 1 × 10 ⁻² Torr (1.33 × 10 ⁻¹ Pa). In the film | membrane board | substrate, it became about 1 * 10 < ¹² > piece / cm < ² >. Furthermore, in the substrate formed in an oxygen atmosphere at 1 × 10 ⁻³ Torr, the CNT density was the same as that at 2 × 10 ⁻³ Torr. From this result, it was confirmed that the CNT density was improved by using the catalyst metal oxide formed in an oxidizing atmosphere. In addition, the higher the pressure in the oxidizing atmosphere, the higher the CNT density.

  As described above, the density of the CNTs vertically grown in a bundle shape can be improved, and as a result, the resistance of the CNT wiring to the via hole can be greatly reduced.

In this example, the case of depositing Co at 0.7 Pa on the Si (100) substrate on which TiN is deposited to 20 nm by sputtering is used, and Ar: O ₂ = 1: 1. And a case where a Co oxide film was formed at 0.7 Pa. The thicknesses of the Co film and the Co oxide film were each set to 30 nm.

  A bundle of CNTs was grown on the substrate thus obtained in the direction perpendicular to the substrate under the same conditions as in Example 1.

When sputtering using only Ar gas, the CNT density is about 5 × 10 ¹⁰ pieces / cm ² , and when sputtering using a gas in which O ₂ is mixed with Ar, 5 × 10 ¹¹ pieces / cm ^{2 are used.} It became about. From this, it can be seen that the CNT density was improved by adding the oxidizing gas.

  According to the present invention, since the density of vertically grown CNTs in a bundle shape can be improved, it greatly contributes to reduction of resistance of CNT wiring to holes such as via holes, and is important in applying CNTs. It can be a technique. Therefore, the present invention can be used in technical fields such as semiconductor devices.

The block diagram which shows typically the example of 1 structure of the coaxial vacuum arc deposition apparatus provided with the coaxial vacuum arc deposition source which can be used by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Vacuum chamber 12 Substrate stage 13 Rotation drive means 14 Heating means 15 Coaxial vacuum arc evaporation source 15a Cathode electrode 15b Anode electrode 15c Trigger electrode 15d Insulator 15e Trigger power supply 15f Arc power supply 15g DC voltage source 15h Capacitor unit 16 Oxidizing gas introduction System 16a, 16c Valve 16b Mass flow controller 16d Gas cylinder 17 Vacuum exhaust system 17a Conductance valve 17b Turbo molecular pump 17c Valve 17d Rotary pump 18 Controller S Substrate

Claims (3)

The substrate you have a oxide layer of catalytic metal used as CNT growth catalyst layer, by supplying the CNT growth process gas to the substrate, the CNT growth method for growing a CNT on the substrate,
The catalyst metal oxide layer is formed by forming catalyst metal fine particles using a coaxial vacuum arc evaporation source, and oxidizing the formed catalyst metal fine particles in an oxidizing atmosphere to obtain catalyst metal oxide fine particles. The oxide fine particles obtained are formed by adhering to the substrate surface,
During CNT growth process, the oxide particles of the catalyst metal from the process gas is reduced to catalyst metal fine particles, CNT growth method characterized by growing CNT on particles of the catalyst metal. Before the time of formation of the oxide layer of Kisawa medium metal, CNT growth method according to claim 1 Symbol mounting, characterized in Rukoto that Nessu substrates pressure. The CNT growth method according to claim 1 or 2 , wherein the oxidizing atmosphere is a gas atmosphere selected from oxygen gas, water vapor, carbon monoxide gas, and carbon dioxide gas.

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