JP2004281159A - Method for patterning carbon fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a patterning method of a film that simplifies the manufacturing process of an electron discharge element, can inexpensively manufacture an image forming apparatus having excellent display quality for a long term, and is made of carbon fibers. <P>SOLUTION: The patterning method includes a step for preparing a substrate 1 whose surface has a lift-off layer 7 and a catalyst layer 6 arranged in a region in which the lift-off layer 7 is not arranged (A), a step for forming a plurality of carbon fibers 4 on the surface of the substrate in the region where at least the catalyst layer 6 is arranged by heating the substrate 1 in an atmosphere containing a hydrocarbon gas (B), and a step for removing the lift-off layer 7 after the step (B) (C). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a carbon fiber patterning method, and further relates to a method of manufacturing an electron-emitting device, a method of manufacturing an electron source having a large number of electron-emitting devices, and a display device configured using the electron source. The present invention relates to a method for manufacturing an image forming apparatus and a light emitting device such as a lamp.
[0002]
[Prior art]
In recent years, there has been an active movement to use carbon fibers such as CNT (Carbon Nano Tube) as electron-emitting devices. Since carbon fibers such as CNTs have a nanometer diameter and a length on the order of microns, they have a very sharp shape with a large aspect ratio. When a carbon fiber is used as an electron-emitting member, the extraction electrodes are opposed to each other, and a positive voltage is applied to the extraction electrodes, an electric field enhancement effect occurs at the tip of the carbon fibers, and the electric field intensity is extremely low at several V / μm. Can emit electrons.
[0003]
There is a trend to use an electron-emitting device using this carbon fiber as an electron source of a field emission display (FED) (see Patent Documents 1 and 2). In the above-mentioned patent document, a method of first preparing CNTs in advance by an arc discharge method or the like, mixing the CNTs with a solvent such as a photoresist to form a paste, and disposing the paste at a desired position by a method such as printing or the like. It has been disclosed. Further, Patent Literature 3 proposes a technique in which CNTs prepared in advance are applied to a substrate by applying, compressing, embedding, or the like to the substrate, and patterning the CNTs by a lithography technique. Further, a method of arranging a catalyst such as Ni, Fe, or Co on a substrate and heating the substrate in a hydrocarbon atmosphere to grow carbon fibers directly on the substrate (referred to as a “seed method”) is also available. It is disclosed in Patent Document 4, Non-Patent Document 1, and the like. This method is a technique useful for cost reduction because an electrode provided with carbon fibers can be easily produced. Patent Document 5 discloses a method for manufacturing an electron source using the seed method.
[0004]
[Patent Document 1]
JP-A-2000-90809
[Patent Document 2]
JP 2000-204304 A
[Patent Document 3]
JP-A-10-149760
[Patent Document 4]
JP 2001-28625 A
[Patent Document 5]
Japanese Patent No. 2903290
[Non-patent document 1]
Science Vol. 283 (1999) 513
[0005]
[Problems to be solved by the invention]
As described above, various methods of patterning the carbon fiber have been devised, but because of their advantages and disadvantages, they are generally not established yet. In particular, when carbon fibers having no orientation characteristics are formed using the seed method, simply designing the catalyst placement region in advance controls the growth region of the carbon fibers growing on the substrate with high accuracy. It was difficult. That is, the carbon fiber having no orientation grows in an arbitrary direction from the catalyst fine particles serving as a growth starting point on the substrate. For this reason, when an electron-emitting device, an electron source, a display, and the like using such a carbon fiber are manufactured, the electron-emitting characteristics of individual electron-emitting devices may vary. It is desired that an electron-emitting device using a carbon fiber solves the above-mentioned problems, further improve characteristics, and propose a simple and inexpensive manufacturing process.
[0006]
Therefore, the present invention has been made to solve the above-described problems, and in particular, can strictly control the position of the carbon fiber, can also simplify the manufacturing process of the electron-emitting device, and improve the electron-emitting characteristics. The present invention also provides a method of patterning a carbon fiber, an electron-emitting device, an electron source, an image forming apparatus, and a method of manufacturing a light-emitting device that can be performed.
[0007]
[Means for Solving the Problems]
The present invention has been made intensively in order to solve the above-mentioned problems, and has the following configuration.
[0008]
That is, the present invention relates to a method for patterning a film composed of a large number of carbon fibers, comprising: (A) a substrate having, on its surface, a lift-off layer and a catalyst layer disposed in a region where the lift-off layer is not disposed. And (B) forming a plurality of carbon fibers on the surface of the substrate at least in a region where the catalyst layer is disposed by heating the substrate in an atmosphere containing a hydrocarbon gas. And (C) a step of removing the lift-off layer after the step (B).
[0009]
The present invention also relates to a method of manufacturing an electron-emitting device having a large number of carbon fibers, wherein (A) an electrode layer, a lift-off layer covering a part of the surface of the electrode layer, and the lift-off layer. Preparing a substrate having a catalyst layer disposed on the surface of the electrode layer, and (B) heating the substrate in an atmosphere containing a hydrocarbon gas so that at least the catalyst layer is disposed. A step of forming a plurality of carbon fibers on the electrode layer in the region that has been set, and (C) a step of removing the lift-off layer after the step (B).
[0010]
In the method of patterning a film made of a large number of carbon fibers and the method of manufacturing an electron-emitting device according to the present invention, the temperature at which the substrate is heated is preferably lower than 600 ° C. Further, it is preferable that the catalyst contains any of Pd, Co, Ni, and Fe. Further, it is preferable that the lift-off layer is made of any one of PSG, BSG, and BPSG.
[0011]
The present invention also provides a method of manufacturing an electron source having a plurality of electron-emitting devices, wherein the electron-emitting device is manufactured by the above-described method of manufacturing an electron-emitting device of the present invention.
[0012]
According to another aspect of the invention, there is provided a method of manufacturing an image forming apparatus having an electron source and a light emitting member, wherein the electron source is manufactured by the above-described method of manufacturing an electron source of the present invention.
[0013]
Further, the present invention is a method for manufacturing a light emitting device having an electron emitting element and a light emitting member, wherein the electron emitting element is manufactured by the above method for manufacturing an electron emitting element of the present invention.
[0014]
ADVANTAGE OF THE INVENTION According to this invention, it is possible to pattern precisely the macro form of the film | membrane which consists of the aggregate of the carbon fiber of low orientation which was difficult conventionally. Therefore, when an electron-emitting device, an electron source, an image forming apparatus, and the like are manufactured using this method, it is possible to reduce variation in characteristics among a plurality of electron-emitting devices. Further, since the patterning process is simple and inexpensive, a light emitting device such as an electron source, an image forming apparatus (display), and a lamp in which a plurality of electron-emitting devices of the present invention are arranged can be manufactured at low cost and easily. .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the drawings, preferred embodiments of a method of patterning a film made of a large number of carbon fibers of the present invention, an electron-emitting device, an electron source, an image forming apparatus and a method of manufacturing a light-emitting device using the same will be described. An example will be described in detail. 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 thereto unless otherwise specified. Absent. Similarly, the manufacturing process described below is not the only one.
[0016]
The “carbon fiber” or “fiber mainly composed of carbon” in the present invention is mainly composed of carbon and has a large ratio of diameter to length (typically, the aspect ratio (length / diameter) is large). 10 or more, preferably 100 or more, more preferably 1000 or more). Specific examples of carbon fiber materials include carbon nanotubes (CNT), graphite nanofibers (GNF), amorphous carbon fibers, diamond fibers, and mixtures of these at non-stoichiometric ratios.
[0017]
Carbon nanotubes include “single-wall carbon nanotubes (SWCNT)” and “multi-wall carbon nanotubes (MWCNT)”.
[0018]
CNT refers to a basic structure obtained by rolling a graphene sheet into a cylindrical shape (cylindrical shape). The fiber constituted by one graphene sheet tube is SWCNT, and the one in which the graphene sheet tube is contained in another graphene sheet tube is MWCNT. Therefore, the c-axis of the CNT is arranged substantially perpendicular to the axial direction (the longitudinal direction of the fiber).
[0019]
On the other hand, GNF refers to a material in which graphene (smaller than the graphene sheet in the CNT described above) is laminated in the fiber axial direction (longitudinal direction). For this reason, GNF basically refers to one in which a plurality of graphenes are stacked so that the c-axis of the graphene is not parallel to the axial direction of the fiber (the longitudinal direction of the fiber). A platelet type GNF in which the c-axis is substantially parallel to the fiber axial direction (the longitudinal direction of the fiber) is a herringbone type in which conical graphene is stacked in the fiber axial direction. Called. The herringbone type includes a form in which V-shaped graphene sheets are stacked in the fiber axial direction.
[0020]
Hereinafter, a method of manufacturing an electron-emitting device using a method of patterning a film made of a large number of carbon fibers according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0021]
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 plan view of FIG. It is AA 'sectional drawing. Reference numeral 4 denotes a carbon fiber which is an emitter material ("electron emitting material", "electron emitting member").
[0022]
In FIG. 1, an electron-emitting device in which a cathode electrode 3 and an extraction electrode 2 are arranged at intervals on the surface of a substrate 1 and a film 4 made of a plurality of carbon fibers is arranged at a specific portion on the surface of the cathode electrode 3. However, the configuration of the element is not limited to this example, and can be applied to, for example, the configurations shown in FIGS.
[0023]
FIG. 2 shows an example of an element configuration in which the cathode electrode 3 is arranged above the extraction electrode 2, and FIG. 3 shows an example of an element configuration in which the cathode electrode 3 is arranged below the extraction electrode 2. Reference numeral 5 denotes an interlayer insulating layer between the cathode electrode 3 and the extraction electrode 2.
[0024]
As shown in the following steps (1) to (5), an example of a method for manufacturing the electron-emitting device having the configuration shown in FIG. 1 will be described with reference to FIG.
[0025]
(1) The base 1 is sufficiently washed with a detergent, pure water, an organic solvent, or the like, and an electrode material is deposited by a vacuum evaporation method, a sputtering method, or the like. Thereafter, an extraction electrode (gate electrode) 2 and a cathode electrode (cathode electrode) 3 are formed on the substrate 1 by using, for example, a photolithography technique (FIG. 4A).
[0026]
As the substrate 1, quartz glass, glass partially reduced to K or the like by reducing the content of impurities such as Na or the like, blue plate glass, or silicon substrate or the like by sputtering or the like. ₂ , A ceramic such as alumina, or the like can be used.
[0027]
Since the extraction electrode 2 and the cathode electrode 3 are functionally different, different materials may be used, or the same material as the cathode electrode 3 may be used as the material of the extraction electrode 2. The material is appropriately selected from carbon, a metal, a metal nitride, a metal carbide, a metal boride, a semiconductor, a metal compound of a semiconductor, and the like. As the cathode electrode 3, a form having an oxide of a material selected from Ti, Zr, and Nb on at least the surface thereof is preferable. These materials have sufficiently low resistance, are materials that do not hinder or promote the growth of carbon fiber, and are materials that provide good electrical connection with carbon fiber. Selected.
[0028]
(2) A lift-off layer 7 of carbon fiber is deposited on the substrate 1 on which the extraction electrode 2 and the cathode electrode 3 are provided, and the lift-off layer 7 in a region where a carbon fiber is to be formed is removed by a photolithography technique (FIG. 4B). )).
[0029]
Since the lift-off layer 7 is formed to a thickness substantially equal to that of carbon fiber, high-speed film forming property and high-speed etching property, etching selectivity with a substrate or an electrode, heat resistance at a growth temperature of carbon fiber, and the like are required. It becomes. Particularly suitable lift-off layer materials include PSG (Phosphosilicate glass), BSG (Boronsilicate glass), and BPSG (Boron-Phosphosilicate glass). The phosphorus concentration in the PSG film is optimized based on film stress, etching rate, and the like. Generally, the lower the phosphorus concentration, the greater the internal stress. Also, as the phosphorus concentration increases, the surface becomes unstable, but the etching rate increases. The optimum phosphorus concentration in the PSG film as the carbon fiber lift-off layer is about 6 to 10 wt%. Usually, carbon fibers (especially GNF) grow in random directions from catalyst nuclei (catalyst particles). Therefore, by forming the film thickness of the lift-off layer 7 to be equal to the film thickness of the film composed of the aggregate of carbon fibers to be finally obtained, the carbon fiber can be moved in the lateral direction (parallel to the surface of the substrate 1). Growth) can be suppressed, and the growth can be accurately controlled.
[0030]
(3) A large number of catalyst particles 6 are deposited on the substrate 1 having the openings formed in the lift-off layer 7 (FIG. 4C).
[0031]
As the catalyst fine particles, Fe, Co, Ni, Pd or an alloy of a material selected from these (particularly preferably an alloy of Pd and Co) is preferably used. As a method for forming the catalyst particles, a general vacuum evaporation method, application of a catalyst particle dispersion solvent, application of an organometallic complex solution, and the like can be used.
[0032]
(4) The substrate 1 on which the catalyst particles are deposited is heated to about 400 ° C. to 600 ° C. in an atmosphere of carbon monoxide, carbon dioxide and various hydrocarbon gases, preferably a mixture of these gases and hydrogen. In this way, carbon fibers are formed on the base 1 (FIG. 4D).
[0033]
As the hydrocarbon gas, for example, ethylene, methane, propane, propylene, or a vapor of an organic solvent such as ethanol or acetone can be used.
[0034]
(5) The substrate 1 on which the carbon fibers are formed is immersed in an etchant for the lift-off layer 7 to remove the lift-off layer 7 and the carbon fibers on the lift-off layer 7 (FIG. 4E).
[0035]
When PSG or BPSG is used as the lift-off layer 7, a P etch liquid is used as an etchant. P etch liquid is 70% HNO ₃ : 49% HF: H ₂ It is an acid solution having a composition of O = 3: 2: 60 (volume ratio) and is an excellent etchant having the ability to etch PSG only very quickly and selectively. When BSG is used as the lift-off layer 7, a dilute HF solution is used as an etchant. This is 49% HF: H ₂ It is an acid solution having a composition of O = 1: 2 (volume ratio), and is characterized in that the etching rate is 10 times or more faster than that of buffered HF (Buffered HF).
[0036]
Regarding the electron-emitting device of the present invention obtained through the above steps (1) to (5), the position of the electron-emitting point and the operation thereof will be described with reference to FIGS.
[0037]
The electron-emitting device of the present invention obtained through the above steps (1) to (5) is placed in a vacuum device 60 shown in FIG. ^-4 Air was sufficiently exhausted until the pressure reached about Pa. Then, an anode (hereinafter, referred to as “anode”) 61 was provided at a height H of several mm from the substrate 1 using a high-voltage power supply, and a high voltage Va 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 is applied as a drive voltage Vf applied between the electrode 2 and the electrode 3, and a device current If flowing between the extraction electrode 2 and the cathode electrode 3 and an electron emission current flowing through the anode 61 Ie was measured.
[0038]
Incidentally, as a matter of course, the drive voltage Vf is higher in the potential applied to the gate electrode 2 than in the cathode electrode 3. At this time, the portion where the electric field concentrates most is on the anode 61 side of the carbon fiber 4 which is the electron emitting material and on the innermost portion of the gap (gap) between the electrode 2 and the electrode 3. It is considered that electrons are emitted from the place where the electric field concentrates most among the electron-emitting materials located near this electric field concentration point. The Ie characteristics of the device were as shown in FIG. That is, Ie rapidly rises from about half of the applied voltage, and If (not shown) resembled the characteristics of Ie, but its value was sufficiently smaller than Ie. With this electron emission characteristic, it is possible to configure an electron source in which a plurality of the above-described electron-emitting devices are arranged in a matrix on the same substrate, and perform matrix driving for selecting and driving a desired element.
[0039]
Hereinafter, based on this principle, an electron source and an image forming apparatus obtained by arranging a plurality of electron-emitting devices according to the embodiment of the present invention will be described with reference to FIGS.
[0040]
FIG. 7 is a schematic plan view of the electron source according to the embodiment of the present invention, and FIG. 8 is a partially cutaway perspective view of the image forming apparatus according to the embodiment of the present invention.
[0041]
In FIG. 7, reference numeral 81 denotes an electron source base, 82 denotes an X-direction wiring, and 83 denotes 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. 7, the m X-direction wirings 82 are DX ₁ , DX ₂ , ... DX _m Consists of However, the material, thickness, and width of the wiring are appropriately designed. On the other hand, the Y-direction wiring 83 is DY ₁ , DY ₂ ... DY _n And formed in the same manner as the X-direction wiring 82. An interlayer insulating layer (not shown) is provided between the m X-directional wirings 82 and the n Y-directional wirings 83 to electrically separate them (m and n are both common). Is a positive integer).
[0042]
The electron-emitting device 84 according to the embodiment of the present invention is electrically connected to the m X-directional wires 82 and the n Y-directional wires 83 by a connection 85. A scanning signal applying unit (not shown) for applying a scanning signal is connected to the X-direction wiring 82. On the other hand, a modulation signal generating means (not shown) for modulating the amount of electrons emitted from each electron-emitting device is connected to the Y-direction wiring 83. With the above configuration, individual elements can be selected and independently driven.
[0043]
An example of an image forming apparatus configured using the electron sources in the matrix arrangement shown in FIG. 7 will be described with reference to FIG. FIG. 8 shows a display panel of an image forming apparatus using soda lime glass as a glass substrate material. 8, reference numeral 81 denotes an electron source substrate on which a plurality of electron-emitting devices are arranged; 91, a rear plate on which the electron source substrate 81 is fixed; 96, a face plate on which a fluorescent film 94 and a metal back 95 are formed on the inner surface of a glass substrate 93 It is. 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 frit glass or the like. Reference numeral 97 denotes an envelope including a face plate 96, a support frame 92, and a rear plate 91. Reference numeral 84 denotes each electron-emitting device, and reference numerals 82 and 83 denote the X-direction wiring and the Y-direction wiring shown in FIG. In addition, by providing a support (not shown) called a spacer between the face plate 96 and the rear plate 91, the envelope 97 having sufficient strength against atmospheric pressure can be configured.
[0044]
【Example】
Next, more specific examples based on the above embodiment will be described in detail.
[0045]
[Example 1]
This example is an example in which the configuration of the electron-emitting device shown in FIG. 1 in the embodiment is manufactured by the manufacturing method of the present invention.
Hereinafter, a manufacturing process of the electron-emitting device according to the present embodiment will be described in detail with reference to FIG.
[0046]
(Step 1) After sufficiently cleaning the base 1 using a quartz substrate, in order to form the extraction electrode 2 and the cathode electrode 3, first, a 100 nm-thick Ti (not shown) was vapor-deposited on the entire substrate by a sputtering method. . Subsequently, a resist pattern was formed by photolithography using a positive photoresist (AZ1500 / manufactured by Clariant) not shown. Using the patterned photoresist as a mask, the Ti film was subjected to dry etching using Ar gas to pattern the extraction electrode 2 and the cathode electrode 3 having an electrode gap (width of gap) of 5 μm (FIG. 4). (A)).
[0047]
(Step 2) Next, a PSG film serving as a lift-off layer was formed by a thermal CVD method. At a substrate temperature of 350 ° C., TEOS (flow rate 9 SLM, temperature 65 ° C.) and TMOP (flow rate 4 SLM, temperature 60 ° C.) are converted into ozone (90 gN / m). ³ ) And a film was formed to a thickness of 2 μm. At this time, the film formation rate is 90 nm / min, and the time required for forming a film of PSG 2 μm is about 21 minutes, and it is possible to form a film at a very high speed. In addition, when the phosphorus concentration in the PSG film at this time was confirmed by μ-ESCA, it was 8 wt%.
[0048]
Subsequently, a resist pattern was formed by photolithography using a positive photoresist (AZ1500 / manufactured by Clariant) not shown. Using the patterned photoresist as a mask, the PSG film is CF ₄ + H ₂ An opening was formed at a position to be a carbon fiber formation site by performing dry etching using a gas (FIG. 4B).
[0049]
(Step 3) Next, a fine particle film of a Pd-Co alloy was formed by a sputtering method as a carbon fiber growth catalyst. Subsequently, the substrate was heated to form catalyst fine particles having a diameter of 3 to 10 nm (FIG. 4C).
[0050]
(Step 4) Next, heat treatment was performed at 500 ° C. in an ethylene stream diluted with nitrogen. When this was observed in cross section with a scanning electron microscope, a form in which a large number of fibrous carbon fibers bent at a diameter of about 10 nm to 25 nm and extended in a fibrous form were densely formed at a thickness of about 1.5 μm (FIG. 4D) )).
[0051]
(Step 5) Next, unnecessary carbon fibers on the PSG film were lifted off using a P etch solution which is an etchant for the PSG film. At this time, the etching rate was 340 nm / min, and the time required for lift-off was about 6 minutes, so that the carbon fibers could be removed very quickly and with high selectivity. When the cross section was observed with a scanning electron microscope, the carbon fibers at the end of the pattern did not spread so much in the horizontal direction (the direction parallel to the substrate surface), and were densely packed while almost maintaining the shape at the time of growth ( FIG. 4 (e).
[0052]
The electron-emitting device manufactured as described above is installed in a vacuum device 60 as shown in FIG. ^-5 It exhausted sufficiently until it reached Pa. Then, as shown in FIG. 5, Va = 10 kV was applied as an anode (anode) voltage to an anode (anode) electrode 61 at a distance of H = 2 mm from the device. At this time, a drive voltage (voltage applied between the electrodes 2 and 3) was applied to the device, and the flowing device current If and the electron emission current Ie were measured.
[0053]
The If and Ie characteristics of the device were as shown in FIG. That is, Ie rapidly increased from about half of the applied voltage, and an electron emission current Ie of about 1 μA was measured. On the other hand, If was similar to the characteristic of Ie, but its value was at least one digit smaller than Ie. The obtained beam had a substantially rectangular shape elongated in the Y direction and short in the X direction.
[0054]
In addition, stable emission characteristics were obtained from the early stage of driving of the element, and the characteristic variation between the elements was σ / μ = 2.8%.
[0055]
As described above, by employing the method of manufacturing an electron-emitting device using the carbon fiber patterning method according to the present embodiment, the electron-emitting device has high electron emission efficiency and stable characteristics while using a simple and inexpensive manufacturing process. An electron-emitting device was realized.
[0056]
[Example 2]
This example is an example in which 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.
[0057]
(Step 1) After sufficiently cleaning the substrate 1 using a glass substrate, Pt was deposited on the entire substrate by sputtering to form the extraction electrode 2. Subsequently, a resist pattern was formed by photolithography using a positive photoresist (AZ1500 / manufactured by Clariant) not shown. Dry etching was performed using the patterned photoresist as a mask to pattern the extraction electrode 2.
[0058]
(Step 2) Next, SiO to be an interlayer insulating layer is formed by sputtering. ₂ Was deposited to a thickness of 1 μm and Ti serving as a cathode electrode was deposited to a thickness of 100 nm. After forming a resist mask by the same photolithography as in Step 1, the Ti film is ₆ Gas, SiO ₂ About CF ₄ + H ₂ Dry etching using a gas was performed to pattern the interlayer insulating layer 5 and the cathode electrode 3.
[0059]
(Step 3) Next, a BSG film to be a lift-off layer was formed by a thermal CVD method. Subsequently, after forming a resist mask by the same photolithography as in step 1, CF ₄ + H ₂ An opening was formed at a position to be a carbon fiber formation site by performing dry etching using a gas.
[0060]
(Step 4) Same as step 3 of the first embodiment.
[0061]
(Step 5) Same as step 4 of the first embodiment.
[0062]
(Step 6) Next, unnecessary carbon fibers on the BSG film were lifted off using a dilute HF aqueous solution which is an etchant for the BSG film. At this time, the etching rate was 240 nm / min, and the time required for lift-off was about 9 minutes, and the carbon fiber could be removed very quickly and with high selectivity. When the cross section was observed with a scanning electron microscope, the carbon fibers at the end of the pattern did not spread so much in the horizontal direction, and were densely packed with almost the shape at the time of growth.
[0063]
The electron-emitting device manufactured as described above is installed in a vacuum device 60 as shown in FIG. ^-5 It exhausted sufficiently until it reached Pa. Then, as shown in FIG. 5, Va = 10 kV was applied as an anode (anode) voltage to an anode (anode) electrode 61 at a distance of H = 2 mm from the device. At this time, a drive voltage (voltage applied between the electrodes 2 and 3) was applied to the device, and the flowing device current If and the electron emission current Ie were measured.
[0064]
The If and Ie characteristics of the device were as shown in FIG. That is, Ie rapidly increased from about half of the applied voltage, and an electron emission current Ie of about 1 μA was measured. On the other hand, If was similar to the characteristic of Ie, but its value was at least one digit smaller than Ie. The obtained beam had a substantially rectangular shape elongated in the Y direction and short in the X direction.
[0065]
In addition, stable emission characteristics were obtained from the early stage of driving of the element, and the characteristic variation between the elements was σ / μ = 3.1%.
[0066]
As described above, by employing the method of manufacturing an electron-emitting device using the carbon fiber patterning method according to the present embodiment, the electron-emitting device has high electron emission efficiency and stable characteristics while using a simple and inexpensive manufacturing process. An electron-emitting device was realized.
[0067]
[Example 3]
An image forming apparatus obtained by disposing a plurality of electron-emitting devices according to the above embodiment will be described.
[0068]
The electron-emitting devices of Example 1 were arranged in a matrix as shown in FIG.
[0069]
Using this electron source base 81, an anode (anode) substrate 96 having a phosphor 94 is disposed above the electron-emitting device 84 at a distance of 2 mm, and an image forming apparatus shown in FIG. .
[0070]
When the apparatus was driven at a pulse voltage of Vf = 30 V and Va (voltage applied to the anode) = 10 kV, the same characteristics as those of Example 1 were obtained in the image forming apparatus.
[0071]
【The invention's effect】
According to the present invention, it is possible to precisely control the position or the orientation characteristics of a carbon fiber having no orientation characteristics, which has conventionally been difficult, and to perform patterning. Even when an image forming apparatus or the like is manufactured, there is no electrical short circuit between the carbon fiber and the gate electrode, and it is possible to reduce the variation in characteristics between elements while further improving the characteristics.
[0072]
Further, since the patterning process is simple and inexpensive, an electron source having a plurality of electron-emitting devices according to the present invention, an image forming apparatus, and the like can be manufactured inexpensively and easily.
[Brief description of the drawings]
FIG. 1 is a schematic plan view and a cross-sectional view of a first example of an electron-emitting device manufactured by a carbon fiber patterning method of the present invention.
FIG. 2 is a schematic cross-sectional view of a second example of the electron-emitting device manufactured by the carbon fiber patterning method of the present invention.
FIG. 3 is a schematic cross-sectional view of a third example of an electron-emitting device manufactured by the carbon fiber patterning method of the present invention.
FIG. 4 is a schematic view showing a manufacturing process of an electron-emitting device of the first example manufactured by the method of patterning carbon fibers of the present invention.
FIG. 5 is a schematic diagram showing an example of a vacuum device having a measurement evaluation function.
FIG. 6 is a schematic diagram showing electron emission characteristics of the electron-emitting device according to the present invention.
FIG. 7 is a schematic plan view of the electron source according to the embodiment of the present invention.
FIG. 8 is a partially cutaway perspective view of the image forming apparatus according to the embodiment of the present invention.
[Explanation of symbols]
1 Substrate
2 Leader electrode (gate electrode)
3 Cathode electrode (cathode electrode)
4 Carbon fiber as emitter material
5 Interlayer insulation layer
6 Catalyst fine particles
7 Lift-off layer
60 vacuum equipment
61 Anode
62 phosphor
81 Base
82 X direction wiring
83 Y direction wiring
84 electron-emitting device
85 connections
91 Rear plate
92 Support frame
93 glass substrate
94 fluorescent film
95 metal back
96 face plate
97 envelope

Claims (1)

A method of patterning a film made of a large number of carbon fibers,
(A) a step of preparing a substrate having, on its surface, a lift-off layer and a catalyst layer disposed in a region where the lift-off layer is not disposed;
(B) heating the substrate in an atmosphere containing a hydrocarbon gas to form a plurality of carbon fibers on the surface of the substrate at least in a region where the catalyst layer is disposed;
(C) after the step (B), removing the lift-off layer;
A method for patterning a film made of a large number of carbon fibers, characterized by comprising:

Images