JP2005169554A - Method of manufacturing fiber containing carbon, and method of manufacturing electronic device with a plurality of fibers containing carbon, arranged on substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an image forming device, capable of manufacturing an electron source substrate stably without characteristic dispersion and manufacturing the image forming device with excellent display quality over a long period of time, at low cost. <P>SOLUTION: The method of manufacturing the electronic device has a first process for forming a first electrode with a catalyst layer on the surface, and a second electrode without a catalyst layer on the surface, on the substrate, and a second process for growing the fibers containing carbon, on the substrate by heating the substrate in the state of bringing gas containing carbon, into contact with the catalyst layer. In the second process, the length of the fibers containing carbon is measured, and the growth quantity of the fibers containing carbon is controlled based on the measured result. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a substrate having a fiber containing carbon, and a method for manufacturing an electronic device in which a plurality of fibers containing carbon are arranged on a substrate.

  In recent years, there has been an active movement to use carbon fibers such as carbon nanotubes as electron emitting members of cold cathode electron sources. Further, application to electronic devices such as secondary batteries, fuel cells, and hydrogen storage bodies has also been proposed. There is a trend to use this carbon fiber as an electron source for FED (Field Emission Display). The FED is a self-luminous display device including one or a plurality of field emission (FE-type) electron-emitting devices per pixel. If this self-luminous display device, the luminance is comparable to that of a CRT, Power consumption can be achieved, and an image display device that is thinner and lighter than a CRT can be manufactured.

In manufacturing this FED, it is necessary to arrange the electron-emitting devices regularly and accurately at the pixel pitch. Therefore, there are a method of arranging carbon fibers prepared in advance (Patent Document 1, Patent Document 2, Patent Document 3, etc.) and a method of directly growing carbon fibers on a substrate (seed method: Patent Document 4). In the above seed method, catalytic metal fine particles such as Ni, Fe, and Co are arranged on a substrate at a desired position, and when this substrate is heat-treated in hydrocarbon, carbon fibers grow. In this method, carbon fibers can be grown directly on the substrate. Then, after the catalyst is dispersed on the substrate provided with the metal thin film, the cathode electrode is produced by patterning to obtain a cathode electrode in which the catalyst is present in all regions without alignment, and then carbon nanotubes and the like. This technology is useful for cost reduction because it is possible to easily produce an electrode equipped with carbon fiber simply by growing carbon fiber.
JP 2000-90809 A JP 2000-204304 A JP-A-10-149760 JP 2002-150925 A

  As mentioned above, the seed method is a very effective method for forming carbon fibers. However, in the growth process after catalyst formation, especially in the case of growth by thermal CVD, the carbon fiber length may vary between batches. At present, strict growth control is not possible.

  Further, when carbon fiber is used as a cold cathode electron source material, variations in the carbon fiber length directly lead to variations in electron emission characteristics, and electron sources having different characteristics from batch to batch are produced.

  Furthermore, when manufacturing a large-area FED using carbon fiber as an electron source, a technique for controlling and monitoring the growth amount within the substrate is also required, which is very important as a design parameter for the growth apparatus. Come.

  As described above, in a method for manufacturing a device having a fiber containing carbon, there is a demand for a simple and inexpensive method for growing while controlling the length of the growing fiber.

  Therefore, the present invention provides a method for producing a fiber containing carbon and a method for producing an electronic device having a fiber containing carbon, which solve the above problems.

  The present invention has been made in earnest to solve the above-described problems, and has the configuration described below.

  That is, the present invention is a method for producing a substrate having carbon-containing fibers, the first step of preparing a substrate having a catalyst layer on the surface, and the catalyst layer in contact with a gas containing carbon. A second step of growing carbon-containing fibers on the substrate by heating the substrate, and the second step further includes the step of growing the carbon-containing fibers grown on the substrate. The method includes measuring the amount corresponding to the length and controlling the growth rate of the fiber containing carbon grown on the substrate based on the measurement result.

  In the present invention, the first step further includes a step of disposing the first electrode and the second electrode on the substrate, and a step of disposing the catalyst layer on the first electrode, The measurement of an amount corresponding to the length of the carbon-containing fiber is also performed based on a temporal change in current between the first electrode and the second electrode.

  In the present invention, the first step further includes a step of disposing the first electrode and the second electrode on the substrate, and a step of disposing the catalyst layer on the first electrode. In addition, the measurement of the amount corresponding to the length of the carbon-containing fiber is performed based on a change with time of the capacitance between the first electrode and the second electrode.

  In the present invention, the measurement of the amount corresponding to the length of the carbon-containing fiber is performed based on the time change of the reflected light intensity of the irradiated light by irradiating a part of the substrate with light. It is also characterized by this.

  In the present invention, the step of controlling the growth rate of the carbon-containing fiber is performed by controlling the supply amount of the carbon-containing gas.

  In addition, the present invention is a method for manufacturing an electronic device having a plurality of carbon-containing fibers disposed on a substrate, wherein the carbon-containing fibers are manufactured by any one of the above-described manufacturing methods. A method of manufacturing an electronic device. Furthermore, the electronic device is an electron-emitting device that emits electrons from the carbon-containing fiber.

  According to the present invention, a carbon-containing fiber having a stable quality with no variation in fiber length between batches, and an electronic device having a small variation, in which a fiber containing a plurality of carbons is arranged on a substrate, can be easily and inexpensively manufactured. Is possible.

  According to the present invention, it is possible to easily and inexpensively manufacture a substrate having stable quality with no variation in fiber length between batches, and an electronic device having no variation in electron emission characteristics of a plurality of elements arranged on the substrate. Is possible.

  Furthermore, since the manufacturing process is simple and inexpensive, the electron source manufactured by the manufacturing method of the present invention and the image forming apparatus can be manufactured inexpensively and easily.

  Exemplary embodiments of a method for producing a plurality of electronic devices arranged on a substrate having carbon-containing fibers according to the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent. Similarly, the manufacturing process described below is not the only one.

  In the present invention, the carbon-containing fiber refers to a “carbon fiber” such as a so-called carbon nanotube or graphite nanofiber. It can also be said that the fiber is preferably composed mainly of carbon. In particular, the carbon fiber has a nano-sized diameter, and in particular, the carbon fiber has a ratio of the length to the fiber diameter of 10 or more, more preferably 100 or more. The “fiber containing carbon” includes carbon nanotubes, graphite fibers, amorphous carbon fibers, diamond fibers, or a mixture of these at a non-stoichiometric ratio.

  Hereinafter, a method for manufacturing an electronic device in which a plurality of carbon-containing fibers according to an embodiment of the present invention are arranged on a substrate will be described in detail with reference to the drawings. Here, the electron-emitting device will be described as an example. However, the carbon-containing fiber manufacturing method of the present invention is not limited to any electronic device using a carbon-containing fiber (for example, a secondary battery, a fuel cell, a hydrogen storage body). Etc.).

  FIG. 1 is a schematic view showing an example of an electron-emitting device manufactured by using the manufacturing method of the present invention, FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a diagram in FIG. It is AA 'sectional drawing. 4 is a carbon fiber which is an emitter material (“electron emission material”, “electron emission member”).

  In FIG. 1, a cathode electrode (first electrode) 2 and an extraction electrode (second electrode) 3 are arranged on the substrate surface at an interval, and a plurality of carbon fibers are arranged at a specific portion on the surface of the cathode electrode 2. However, the configuration of the device is not limited to this example, and can be applied to the device configuration as shown in FIGS. Reference numeral 5 denotes an interlayer insulating layer of the cathode electrode and the extraction electrode.

  FIG. 2 shows an example of an element configuration in which the cathode electrode 2 is arranged in the upper layer of the extraction electrode 3, and FIG. 3 shows an example of an element configuration in which the cathode electrode 2 is arranged in the lower layer of the extraction electrode 3.

  Further, a manufacturing method and a measuring method of a fiber-length measuring element containing carbon when the electron-emitting device having the configuration of FIG. 1 is manufactured will be described in detail with reference to FIGS.

  As described above, the fiber length measuring element containing carbon can be manufactured directly on the substrate, or can be prepared on a dummy substrate by preparing a dummy substrate.

  Here, an example in which a measuring element is manufactured on a dummy substrate will be described. The measuring element on the dummy substrate is preferably manufactured in the same configuration as the element on the actual substrate, and it is desirable to select a suitable fiber length measuring method depending on the element configuration on the substrate. The fiber length measurement can be performed based on the time change of the resistance or capacitance between the first and second electrodes, or the time change of the reflected light intensity of the light irradiated to the growth portion of the fiber.

  This embodiment is an example in which the fiber length is measured and the feedback to the growth time is performed by changing the resistance of the measuring element on the dummy substrate with respect to the element configuration of FIG. 4A to 4D are schematic views (plan views) showing measurement elements having different electrode intervals Dx on the dummy substrate according to this embodiment.

(1) Quartz glass, glass with partially reduced impurities such as Na, glass partially substituted with K, etc., blue plate glass, laminated body in which SiO ₂ is laminated on a silicon substrate, etc., insulation of ceramics such as alumina The substrate (substrate) 1 is sufficiently washed with a detergent, pure water, an organic solvent, etc., and an electrode material is deposited by a vacuum evaporation method, a sputtering method or the like, and then a cathode is formed on the substrate 1 by using, for example, a photolithography technique. An electrode (cathode electrode) 2 and an extraction electrode (gate electrode) 3 are formed (FIG. 5A). Since the cathode electrode 2 and the extraction electrode 3 are functionally different, different materials may be used, or the same material may be used according to the cathode electrode 2. The material is appropriately selected from carbon, metal, metal nitride, metal carbide, metal boride, semiconductor, semiconductor metal compound, and the like. A particularly suitable material for the cathode electrode 2 is an oxynitride (including a surface oxidation form) of a material selected from Ti, Zr, or Nb, which has a sufficiently low resistance as an electrode material. The material is selected because it is a material that does not inhibit or promote the growth of the carbon fiber, and a material that has a good electrical connection with the carbon fiber.

  (2) A lift-off layer 7 of catalyst fine particles 6 is formed on the substrate 1 provided with the cathode electrode 2 and the extraction electrode 3 by a photolithography technique (FIG. 5B). For the lift-off layer 7, a negative type photoresist can be preferably used.

  (3) Next, catalyst fine particles 6 are deposited on the lift-off layer 7 in which the openings are formed (FIG. 5C). As the catalyst fine particles, Fe, Co, Ni, Pd, or an alloy of materials selected from these (particularly preferably, an alloy of Pd and Co) can be used as a growth nucleus for forming carbon fibers. As a method for forming the catalyst, a general vacuum vapor deposition method, coating of a catalyst ultrafine particle dispersion solvent, coating of an organometallic complex solution, or the like can be used.

  (4) The substrate on which the catalyst fine particles are deposited is immersed in an etchant of the lift-off layer, thereby removing the lift-off layer and the catalyst fine particles on the lift-off layer (FIG. 5D).

  (5) The substrate on which the catalyst fine particles have been patterned is heated (400 ° C. to 600 ° C.) in an atmosphere of carbon fiber source gas (carbon monoxide, carbon dioxide, various hydrocarbon gases, or a mixed gas of these gases and hydrogen). To form a carbon fiber. As the hydrocarbon gas, for example, ethylene, methane, propane, propylene, or vapor of an organic solvent such as ethanol or acetone can be used.

  By monitoring the resistance of measuring elements with different electrode spacing Dx on the dummy substrate when forming the carbon fiber, the fiber length of the elements on the substrate can be estimated, and a substrate with no variation between batches can be stably formed. Can do it.

That is, when the carbon fiber is formed, (resistor) ⁻¹ of the measurement elements of FIGS. 4A to 4D schematically changes stepwise as shown in FIG. 6A. More specifically, regarding the measurement element (d), (resistance) ^{−1 to} 0 when t <td, 1 / (Dd · R) when t = td, and almost linear with respect to time when t> td. To increase. Here, R is a resistance (constant) per unit length of the fiber containing carbon.

  Conversely, the resistance when one fiber is short-circuited with a measuring element with a gap interval Dx is Dx · R, and tracking the time tx when Dx · R for each measuring element is followed, the effective of the fiber The length can be estimated (FIG. 6B).

With respect to the electron-emitting device obtained through the above steps, the position and operation of the electron emission point in the emitter region will be described with reference to FIGS. This element having a gap (gap) length of several μm was placed in a vacuum device 60 as shown in FIG. 7, and was sufficiently evacuated until it reached about 10 ⁻⁴ Pa by a vacuum exhaust device. Then, using a high-voltage power source, an anode (hereinafter referred to as an anode) 61 was provided at a height H of several millimeters from the substrate, and a high voltage Va consisting of several kilovolts was applied. The anode 61 is provided with a phosphor 62 coated with a conductive film. A pulse voltage of about several tens of volts was applied as the drive voltage Vf applied between the electrodes 2 and 3, and the flowing device current If and the electron emission current Ie were measured. As a matter of course, the drive voltage Vf is higher in potential applied to the gate electrode 2 than in the cathode electrode 2. At this time, the portion where the electric field is most concentrated is the portion closest to the anode 61 of the carbon fiber 4 which is the electron emission material, and the innermost portion of the gap. It is considered that electrons are emitted from a place where the electric field concentrates most among the electron emission materials located near the electric field concentration point. The Ie characteristic of the element was as shown in FIG. That is, Ie suddenly rises from about half of the applied voltage, and If not shown is similar to the characteristics of Ie, but its value is sufficiently smaller than Ie.

  With this electron emission characteristic, a simple matrix drive in which an electron source in which a plurality of electron emission elements are arranged in a matrix on the same substrate is configured, and a desired element is selected and driven is possible.

  In the electron-emitting device manufactured by the fiber length control method of the present invention, the characteristic variation between the elements was 3% or less, whereas in the method not using the fiber length control method of the present invention, the characteristic variation between the devices was 8%. % And the threshold voltage variation was about 3 to 5 V / μm.

  Hereinafter, based on this principle, an electron source and an image forming apparatus obtained by arranging a plurality of electron-emitting devices according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 9 is a schematic plan view of the electron source according to the embodiment of the present invention, FIG. 10 is a partially broken perspective view of the image forming apparatus according to the embodiment of the present invention, and FIG. 1 is a block diagram of an image forming apparatus according to an embodiment.

In FIG. 9, 81 is an electron source substrate, 82 is an X direction wiring, and 83 is a Y direction wiring. 84 is an electron-emitting device according to the embodiment of the present invention, and 85 is a connection. In FIG. 9, m X-direction wirings 82 are made of DX ₁ , DX ₂ ... DX _m , and are made of a metal wiring material formed by a vapor deposition method. However, the wiring material, film thickness, and width are appropriately designed. On the other hand, the Y-direction wiring 83 is composed of n wirings DY ₁ , DY ₂ ... DY _n and is formed in the same manner as the X-direction wiring 82.

An interlayer insulating layer (not shown) is provided between the m X-direction wirings 82 and the n Y-direction wirings 83 to electrically isolate both (m and n are both A positive integer). An interlayer insulating layer (not shown) is made of, for example, SiO ₂ .

  A pair of electrodes (not shown) constituting the electron-emitting device 84 according to the embodiment of the present invention is electrically connected by a connection 85 made of m X-direction wirings 82, n Y-direction wirings 83, a conductive metal, and the like. Connected.

  The X-direction wiring 82 is connected to scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the electron-emitting devices 84 according to the embodiment of the present invention arranged in the X direction. On the other hand, the Y-direction wiring 83 is connected to modulation signal generating means (not shown) for modulating each column of the electron-emitting devices 84 according to the embodiment of the present invention arranged in the Y direction according to an input signal. The The drive voltage applied to each electron-emitting device is supplied as a difference voltage between the scanning signal and the modulation signal applied to the device.

  In the above configuration, individual elements can be selected using a simple matrix wiring and can be driven independently. An image forming apparatus configured using such a simple matrix electron source will be described with reference to FIG.

  FIG. 10 shows a display panel of the image forming apparatus. In FIG. 10, 81 is an electron source substrate on which a plurality of electron-emitting devices are arranged, 91 is a rear plate on which the electron source substrate 81 is fixed, and 96 is a face having a fluorescent film 94 and a metal back 95 formed on the inner surface of a glass substrate 93. It is a plate. Reference numeral 92 denotes a support frame, and a rear plate 91 and a face plate 96 are connected to the support frame 92 using an adhesive such as frit glass. Reference numeral 97 denotes an envelope, which is configured to be sealed, for example, by baking in a vacuum at a temperature range of 450 degrees for 10 minutes. Reference numeral 84 denotes an electron emission portion, and reference numerals 82 and 83 denote an X direction wiring and a Y direction wiring respectively connected to a pair of element electrodes of the electron emission element according to the embodiment of the present invention.

  The envelope 97 is composed of the face plate 96, the support frame 92, and the rear plate 91 as described above. Further, by installing a support body (not shown) called a spacer between the face plate 96 and the rear plate 91, an envelope 97 having sufficient strength against atmospheric pressure can be configured. The metal back 95 is formed by performing a smoothing process (usually called “filming”) on the inner surface of the phosphor film after the phosphor film is fabricated, and then depositing Al using vacuum deposition or the like. Can do.

  As described above, the electron-emitting device according to the embodiment of the present invention has the following basic characteristics with respect to the emission current Ie. That is, there is a clear threshold voltage Vth for electron emission, and electron emission occurs only when a voltage equal to or higher than Vth is applied. For voltages above the electron emission threshold, the emission current also changes with changes in the voltage applied to the device. For this reason, when a pulsed voltage is applied to the device, for example, electron emission does not occur even when a voltage lower than the electron emission threshold is applied, but when a voltage higher than the electron emission threshold is applied, the electron beam is not Is output. At that time, the intensity of the output electron beam can be controlled by changing the pulse peak value Vm. Further, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.

  The configuration of the image forming apparatus described here is an example of an image forming apparatus to which the present invention can be applied, and various modifications can be made based on the technical idea of the present invention.

  Next, more specific examples based on the above embodiment will be described in detail.

  In this example, the structure of the electron-emitting device shown in FIG. 1 in the embodiment is manufactured by the manufacturing method of the present invention.

  Since the element on the substrate and the measuring element on the dummy substrate are manufactured in exactly the same way up to the formation of the carbon fiber, the elements on the dummy substrate are similarly manufactured in the manufacturing process described in detail below.

  The manufacturing process of the electron-emitting device according to this example will be described in detail with reference to FIGS.

(Process 1)
After sufficiently cleaning the substrate 1 using a quartz substrate, in order to form the extraction electrode 3 and the cathode electrode 2, Ti having a thickness of 100 nm (not shown) was first deposited on the entire substrate by sputtering. Subsequently, a resist pattern was formed by photolithography using a positive photoresist (not shown). Using the patterned photoresist as a mask, dry etching using Ar gas was performed on the Ti film, and the extraction electrode 3 and the cathode electrode 2 having an electrode gap (gap width) of 5 μm were patterned (FIG. 5). (A)).

(Process 2)
Next, using a negative photoresist as a lift-off layer, a resist pattern having an opening in the catalyst forming portion was formed (FIG. 5B).

(Process 3)
Next, a fine particle film of a Pd—Co alloy was formed by sputtering as a carbon fiber growth catalyst (FIG. 5C).

(Process 4)
Next, the substrate that had been formed up to the formation of catalyst fine particles was immersed in a remover to lift off unnecessary catalyst fine particles on the photoresist.

  Subsequently, the substrate was heated and heat-treated in hydrogen. At this stage, catalyst fine particles having a diameter of about 3 to 10 nm were formed. (FIG. 5D).

  Through the steps described above, a substrate having been subjected to pattern formation of catalyst fine particles and a similar dummy substrate were produced. However, when the gap between the element electrodes on the base is D, the interelectrode gap Dx (x = 1 to 5) of the fiber length measuring element on the dummy base is D1 = (1/5) D, D2 = (2 / 5) D, D3 = (3/5) D, D4 = (4/5) D, D5 = D.

(Process 5)
Next, the substrate prepared according to steps 1 to 4 and the dummy substrate were heat-treated at 500 ° C. in an ethylene stream diluted with nitrogen.

  During the heat treatment, the resistances of five types of fiber length measuring elements with different gap intervals formed on the dummy substrate were monitored. At this time, (1 / resistance) change of each measuring element was as shown in FIG. That is, (1 / resistance) of the measuring element 1 rises stepwise in about 3 minutes of heat treatment, then the measuring element 2 rises in about 5 minutes, then measuring element 3 in about 7 minutes, and measuring element 4 in about 9 minutes. As a result, the heat treatment was finished in 10 minutes.

  When this was cross-sectionally observed with a scanning electron microscope, a form in which a large number of carbon fibers extending in a fiber shape while being bent at about several tens of nanometers were densely packed at a thickness of about 1.5 μm (FIG. 5E). .

The electron-emitting device produced as described above was installed in a vacuum device 60 as shown in FIG. 7, and was sufficiently evacuated by a vacuum exhaust device until it reached 2 × 10 ⁻⁵ Pa. Then, as shown in FIG. 6, Va = 10 KV was applied as the anode (anode) voltage to the anode (anode) electrode 61 which was H = 2 mm away from the element. At this time, a pulse voltage of drive voltage (voltage applied between the electrodes 2 and 3) Vf = 30 V was applied to the element, and the flowing element current If and electron emission current Ie were measured.

  The If and Ie characteristics of the device were as shown in FIG. That is, Ie increased rapidly from about half of the applied voltage, and an electron emission current Ie of about 1 μA was measured when Vf was 30V. On the other hand, If was similar to the characteristics of Ie, but its value was one or more orders of magnitude smaller than Ie.

  In addition, stable emission characteristics were obtained from the early stage of driving of the element, and there was no electrical short circuit between the carbon fiber and the gate electrode, and the characteristic variation between the elements was σ / μ = 2.4%.

  When manufactured in the same manner without controlling the fiber length by the dummy substrate, the variation in characteristics between batches was 3.8%, and the variation in characteristics between the same batch elements was σ / μ = 2.8%.

  As described above, by using a manufacturing method of an electronic device in which a carbon-containing fiber according to the present embodiment and a plurality of carbon-containing fibers are arranged on the substrate, using a simple and inexpensive manufacturing process, An electron-emitting device having stable characteristics with no variation in characteristics between batches was realized.

  In this example, the configuration of the electron-emitting device shown in FIG. 2 in the embodiment is manufactured by the manufacturing method of the present invention.

  Hereinafter, the manufacturing process of the electron-emitting device according to the present embodiment will be described in detail.

(Process 1)
After sufficiently cleaning the substrate 1 using a quartz substrate, in order to form the extraction electrode 3, first, 5 nm thick Ti and 100 nm thick Pt were vapor-deposited on the entire substrate by electron beam evaporation. . Subsequently, a resist pattern was formed by photolithography using a positive photoresist (not shown). Using the patterned photoresist as a mask, the Ti film was dry-etched using Ar gas to pattern the extraction electrode 3.

(Process 2)
Next, as an interlayer insulating layer 5, SiO ₂ was deposited to a thickness of 3 μm by PCVD.

  Further, in order to form the cathode electrode 2, Ti having a thickness of 100 nm was deposited by sputtering.

(Process 3)
Next, a negative photoresist was used as a lift-off layer to form a resist pattern having an opening in the catalyst formation portion, and a Pd—Co alloy fine particle film was formed by sputtering as a carbon fiber growth catalyst.

  Further, the substrate after the formation of catalyst fine particles was immersed in a remover to lift off unnecessary catalyst fine particles on the photoresist. Subsequently, the substrate was heated to 200 ° C., and heat treatment was performed in a hydrogen-containing atmosphere to reduce the catalyst particles.

(Process 4)
Subsequently, a resist pattern was formed by photolithography using a positive photoresist (not shown). Using the patterned photoresist as a mask, reactive ion etching was performed to pattern the cathode electrode 2 and the interlayer insulating layer 5.

(Process 5)
Next, the substrate prepared according to steps 1 to 4 was heated at 500 ° C. for 10 minutes in a 0.1% ethylene stream diluted with nitrogen.

  During the heat treatment, the effective fiber length grown on the substrate was estimated by irradiating the catalyst fine particle forming portion with light and monitoring the reflected light intensity. However, the fiber effective length-reflected light intensity correlation data was acquired in advance under the same device configuration and growth conditions.

  When this was cross-sectionally observed with a scanning electron microscope, a form was formed in which a large number of carbon fibers extending in a fiber shape while being bent at a diameter of about several tens of nm were densely packed at a thickness of about 1.5 μm.

The electron-emitting device produced as described above was installed in a vacuum device 60 as shown in FIG. 7, and was sufficiently evacuated by a vacuum exhaust device until it reached 2 × 10 ⁻⁵ Pa. Then, as shown in FIG. 7, Va = 10 KV was applied as an anode (anode) voltage to an anode (anode) electrode 61 that was H = 2 mm away from the element. At this time, a pulse voltage of drive voltage (voltage applied between the electrodes 2 and 3) Vf = 30 V was applied to the element, and the flowing element current If and electron emission current Ie were measured.

  The If and Ie characteristics of the device were as shown in FIG. That is, Ie increased rapidly from about half of the applied voltage, and electron emission was confirmed from Vf of about 12V. An electron emission current Ie of about 1 μA was measured at Vf25V. On the other hand, If was similar to the characteristics of Ie, but its value was one or more orders of magnitude smaller than Ie.

  In addition, stable emission characteristics were obtained from the early stage of driving of the device, there was no electrical short circuit between the carbon fiber and the gate electrode, and the device characteristic variation was σ / μ = 2.6%.

  When manufactured in the same manner without controlling the fiber length by the dummy substrate, the variation in characteristics between batches was 3.9%, and the variation in characteristics between the same batch elements was σ / μ = 3.0%.

  As described above, by using a manufacturing method of an electronic device in which a carbon-containing fiber according to the present embodiment and a plurality of carbon-containing fibers are arranged on the substrate, using a simple and inexpensive manufacturing process, An electron-emitting device having stable characteristics with no variation in characteristics between batches was realized.

  In this example, the configuration of the electron-emitting device shown in FIG. 3 in the embodiment is manufactured by the manufacturing method of the present invention.

  Hereinafter, the manufacturing process of the electron-emitting device according to the present embodiment will be described in detail.

(Process 1)
After sufficiently cleaning the substrate 1 using a quartz substrate, in order to form the cathode electrode 2, Ti having a thickness of 100 nm (not shown) was first vapor-deposited on the entire substrate by sputtering. Subsequently, a resist pattern was formed by photolithography using a positive photoresist (not shown). Using the patterned photoresist as a mask, the Ti film was dry-etched using Ar gas to pattern the cathode electrode 2.

(Process 2)
Next, a negative photoresist was used as a lift-off layer to form a resist pattern having an opening in the catalyst formation portion, and a Pd—Co alloy fine particle film was formed by sputtering as a carbon fiber growth catalyst.

  Further, the substrate after the formation of catalyst fine particles was immersed in a remover to lift off unnecessary catalyst fine particles on the photoresist. Subsequently, the substrate was heated to 200 ° C. and heat-treated in a hydrogen stream diluted with nitrogen to reduce the catalyst particles.

(Process 3)
Next, as an interlayer insulating layer 5, SiO ₂ was deposited to a thickness of 3 μm by PCVD.

  Furthermore, in order to form the extraction electrode 3, Ti having a thickness of 5 nm and Pt having a thickness of 100 nm were continuously deposited by an electron beam evaporation method.

(Process 4)
Subsequently, a resist pattern was formed by photolithography using a positive photoresist (not shown). Using the patterned photoresist as a mask, reactive ion etching was performed to pattern the extraction electrode 3 and the interlayer insulating layer 5.

(Process 5)
Next, the substrate prepared according to steps 1 to 4 and the dummy substrate were heated at 500 ° C. in an ethylene stream diluted with nitrogen.

  During the heat treatment, the fiber length on the substrate was controlled by monitoring the capacitance of the fiber length measuring element formed on the dummy substrate.

  When this was cross-sectionally observed with a scanning electron microscope, a form was formed in which a large number of carbon fibers extending in a fiber shape while being bent at a diameter of about several tens of nm were densely packed at a thickness of about 1.5 μm.

The electron-emitting device produced as described above was installed in a vacuum device 60 as shown in FIG. 7, and was sufficiently evacuated by a vacuum exhaust device until it reached 2 × 10 ⁻⁵ Pa. Then, as shown in FIG. 7, Va = 10 KV was applied as an anode (anode) voltage to an anode (anode) electrode 61 that was H = 2 mm away from the element. At this time, a pulse voltage of drive voltage (voltage applied between the electrodes 2 and 3) Vf = 30 V was applied to the element, and the flowing element current If and electron emission current Ie were measured.

  The If and Ie characteristics of the device were as shown in FIG. That is, Ie increased rapidly from about half of the applied voltage, and electron emission was confirmed from Vf of about 12V. An electron emission current Ie of about 1 μA was measured at Vf25V. On the other hand, If was similar to the characteristics of Ie, but its value was one or more orders of magnitude smaller than Ie.

  In addition, stable emission characteristics were obtained from the early stage of driving of the device, there was no electrical short circuit between the carbon fiber and the gate electrode, and the variation in characteristics between the devices was σ / μ = 2.5%.

  When manufactured in the same manner without controlling the fiber length by the dummy substrate, the characteristic variation between batches was 4.1%, and the characteristic variation between the same batch elements was σ / μ = 3.0%.

  As described above, by using a manufacturing method of an electronic device in which a carbon-containing fiber according to the present embodiment and a plurality of carbon-containing fibers are arranged on the substrate, using a simple and inexpensive manufacturing process, An electron-emitting device having stable characteristics with no variation in characteristics between batches was realized.

  An image forming apparatus obtained by arranging a plurality of electron-emitting devices according to the above embodiment will be described.

  The electron-emitting devices of Example 1 were arranged in a matrix as shown in FIG. 10, and the electron source substrate 81 was completed.

  Using this electron source substrate 81, an anode (anode) substrate 96 having a phosphor 94 is disposed on the electron-emitting device 84 at a distance of 2 mm, thereby producing the image forming apparatus shown in FIG. .

  When driven at a pulse voltage of Vf = 30 V and Va (voltage applied to the anode) = 10 kV, an image forming apparatus having stable characteristics between batches was obtained in the image forming apparatus as in Example 1. .

It is the 1st example of the electron emission element produced with the manufacturing method of the base | substrate which has a fiber containing the carbon of this invention, The typical top view and sectional drawing. It is the 2nd example of the electron-emitting element produced with the manufacturing method of the base | substrate which has a fiber containing the carbon of this invention, and is the typical sectional drawing. It is the 3rd example of the electron-emitting element produced with the manufacturing method of the base | substrate which has a fiber containing the carbon of this invention, and is the typical sectional drawing. It is a schematic diagram of the fiber length measuring element produced on the dummy base | substrate in the manufacturing method of the electron-emitting element of a 1st example. It is a schematic diagram which shows the manufacturing process of the electron emission element of the 1st example produced with the manufacturing method of the base | substrate which has a fiber containing the carbon of this invention. It is a figure expressing resistance of a fiber length measuring element, change, and time change of effective fiber length in a manufacturing method of a substrate which has a fiber containing carbon of the present invention. It is a schematic diagram which shows an example of the vacuum apparatus provided with the measurement evaluation function. It is a schematic diagram which shows the electron emission characteristic of the electron-emitting device by this invention. 1 is a schematic plan view of an electron source according to an embodiment of the present invention. 1 is a partially broken perspective view of an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

1 Substrate 2 Cathode electrode (cathode electrode)
3 Lead electrode (gate electrode)
4 Carbon fiber as emitter material 5 Interlayer insulating layer 6 Catalyst fine particle 7 Lift-off layer 60 Vacuum device 61 Anode 62 Phosphor 81 Base 82 X direction wiring 83 Y direction wiring 84 Electron emitting element 85 Connection 91 Rear plate 92 Support frame 93 Glass base 94 phosphor film 95 metal back 96 face plate 97 envelope

Claims (7)

A method for producing carbon-containing fiber,
A first step of preparing a substrate having a catalyst layer on the surface;
A second step of growing a fiber containing carbon on the base by heating the base in a state where the catalyst layer is in contact with a gas containing carbon; and
The second step further includes
Measuring the amount corresponding to the length of the fiber containing carbon grown on the substrate, and controlling the growth rate of the fiber containing carbon grown on the substrate based on the measurement result. A method for producing a substrate having a carbon-containing fiber. The first step further includes a step of disposing the first electrode and the second electrode on the substrate, and a step of disposing the catalyst layer on the first electrode,
Measurement of the amount corresponding to the length of the carbon-containing fiber,
The method for producing a substrate having a carbon-containing fiber according to claim 1, wherein the method is performed based on a temporal change in current between the first electrode and the second electrode. The first step further includes a step of disposing the first electrode and the second electrode on the substrate, and a step of disposing the catalyst layer on the first electrode,
Measurement of the amount corresponding to the length of the carbon-containing fiber,
2. The method for producing a substrate having carbon-containing fibers according to claim 1, wherein the method is performed based on a temporal change in capacitance between the first electrode and the second electrode. Measurement of the amount corresponding to the length of the carbon-containing fiber,
The method for producing a substrate having a fiber containing carbon according to claim 1, wherein the method is performed based on a temporal change in reflected light intensity of the irradiated light by irradiating a part of the substrate with light.   5. The carbon-containing fiber according to claim 1, wherein the step of controlling the growth rate of the carbon-containing fiber is performed by controlling a supply amount of the carbon-containing gas. A method for producing a substrate having the same. A method of manufacturing an electronic device having a plurality of carbon-containing fibers disposed on a substrate,
An electronic device manufacturing method, wherein the carbon-containing fiber is manufactured by the manufacturing method according to claim 1.   The electronic device according to claim 6, wherein the electronic device is an electron-emitting device that emits electrons from the carbon-containing fiber.

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