JP2010010017A - Electron emitting element, electron source and manufacturing method of them, and image display device - Google Patents

Abstract

The present invention provides a method for manufacturing an electron-emitting device having a good carbon film on a substrate on which a layer mainly composed of SiO ₂ is laminated by a CVD method.
A substrate composed mainly of SiO ₂ having an N element ratio of 2% or less is formed on a substrate by a CVD method to form a substrate, on which device electrodes, 3 and a conductive layer are formed. A film 4 is formed, and a carbon film 6 is further deposited by an activation process.
[Selection] Figure 2

Description

  The present invention relates to an electron-emitting device used in a flat panel display, a method for manufacturing the same, an electron source in which the electron-emitting device is arranged, and an image display device configured using the electron source.

  Conventionally, two types of electron-emitting devices are known: a thermionic source and a cold cathode electron source. Cold cathode electron sources include field emission devices (FE devices), metal / insulating layer / metal devices (MIM devices), surface conduction electron emitters, and the like.

Patent Document 1 discloses a configuration and a manufacturing method of a surface conduction electron-emitting device. In such an electron-emitting device, a pair of device electrodes are formed on a substrate, a conductive film is formed between the device electrodes, a voltage is applied to the conductive film to form a gap, and an activation process is performed. A carbon film is deposited in the vicinity of the gaps by a process called “a”. Patent Document 1 discloses a configuration in which a SiO ₂ layer is provided on a substrate to prevent diffusion of sodium contained in the substrate into the element.

JP 2004-207131 A

The sodium diffusion preventing layer made of SiO ₂ as described in Patent Document 1 can be formed by a sputtering method, a vacuum evaporation method, an electron beam evaporation method, or a CVD (Chemical Vapor Deposition) method. . Among these, the sputtering method is disadvantageous in terms of time and cost because the film formation time is long and it is necessary to use a vacuum apparatus. On the other hand, the CVD method can efficiently form a film. However, when the electron-emitting device is formed on the substrate on which the SiO ₂ layer is formed by the CVD method, when the above-described activation treatment is performed, a good carbon is obtained. There was a problem that the film could not be deposited (activation failure).

An object of the present invention is to provide a method of manufacturing an electron-emitting device having a good carbon film on a substrate in which a layer mainly composed of SiO ₂ is laminated by a CVD method, and to provide a high-quality electron-emitting device There is to do. It is another object of the present invention to provide an electron source including a plurality of the electron-emitting devices and a manufacturing method thereof, and to provide a high-quality image display apparatus using the electron source.

According to a first aspect of the present invention, a pair of element electrodes on a substrate, a conductive film having a first gap formed between the element electrodes, and a carbon having a second gap at least in the first gap. A method of manufacturing an electron-emitting device including a film,
Forming a layer mainly composed of SiO ₂ on a substrate by a CVD method to form a substrate;
Forming a pair of device electrodes on the substrate;
Forming a conductive film between the element electrodes;
Forming a first gap in the conductive film;
Forming a carbon film having a second gap by applying a voltage between the pair of device electrodes in an atmosphere containing a carbon-containing gas;
Have
The element ratio of N in the layer mainly composed of SiO ₂ is 2% or less.

According to a second aspect of the present invention, a pair of element electrodes, a conductive film having a first gap formed between the element electrodes, a carbon film having a second gap at least in the first gap, A method of manufacturing an electron source having a plurality of electron-emitting devices having a substrate on a substrate,
Forming a layer mainly composed of SiO ₂ on a substrate by a CVD method to form a substrate;
Forming a plurality of device electrode pairs on the substrate;
In each element electrode pair, forming a conductive film between the element electrodes;
Forming a first gap in the conductive film;
Forming a carbon film having a second gap by applying a voltage between the pair of device electrodes in an atmosphere containing a carbon-containing gas;
Have
The element ratio of N in the layer mainly composed of SiO ₂ is 2% or less.

In the present invention, it is preferable that the layer mainly composed of SiO ₂ is formed by a CVD method using SiH ₄ and N ₂ O.

According to a third aspect of the present invention, a pair of element electrodes on the substrate, a conductive film having a first gap formed between the element electrodes, and a carbon having a second gap at least in the first gap. An electron-emitting device comprising a film,
The substrate is a layer mainly composed of SiO ₂ formed on a substrate by a CVD method, wherein the element ratio of N is 2% or less.

  A fourth aspect of the present invention is an electron source having a plurality of electron-emitting devices on a substrate, wherein the electron-emitting device is the electron-emitting device of the present invention.

  According to a fifth aspect of the present invention, there is provided the second substrate on which the electron source according to the present invention and a light emitter that emits light by irradiation of electrons emitted from the electron emitter facing the electron emitter of the electron source are disposed. Is an image display device characterized by being arranged opposite to each other.

According to the present invention, an electron-emitting device having a good carbon film and excellent electron emission characteristics is manufactured on a substrate on which layers having SiO ₂ as a main component are laminated. Therefore, according to the present invention, an electron source including a plurality of the electron-emitting devices can be efficiently manufactured, and a high-quality image display apparatus can be provided.

The present inventors examined in detail the relationship between the layer mainly composed of SiO ₂ and the activation failure, and the element ratio of N contained in the layer mainly composed of SiO ₂ has an influence on the activation treatment. I found out that I was giving. Therefore, when activation was performed using a substrate on which SiO ₂ layers having different N ratios were formed, it was found that if the N element ratio was 2% or less, activation failure did not occur. Achieved.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the dimensions, materials, shapes, relative arrangements, and the like of components described in the following embodiments.

1A and 1B are diagrams schematically showing a preferred embodiment of the electron-emitting device of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. In the figure, 1 is a substrate, 2 and 3 are element electrodes, 4 is a conductive film, 5 is a first gap formed in the conductive film 4, 6 is a carbon film, 7 is a second gap, and 8 is SiO. A layer having ₂ as a main component (hereinafter referred to as a SiO ₂ layer for convenience) 10 is a substrate formed by laminating a SiO ₂ layer 8 on a substrate 1.

In the present invention, the substrate 10 is used by laminating the SiO ₂ layer 8 on the substrate. As the substrate 1, for example, quartz glass, glass with reduced impurity content such as Na, glass substrate such as blue plate glass, ceramic substrate such as alumina, and the like are preferably used. Considering availability and cost, low alkali glass, for example, PD200 manufactured by Asahi Glass Co., Ltd. is suitable. The substrate contains alkali metal, particularly Na, which is not preferable when it diffuses into the element. In the present invention, since the SiO ₂ layer 8 is used in a stacked manner, diffusion of Na into the element is difficult. Is prevented.

The SiO ₂ layer 8 according to the present invention is a layer mainly composed of SiO ₂ . In the present invention, the element ratio of N contained in the SiO ₂ layer 8 is 0.5% or more and 2% or less.

The SiO ₂ layer 8 according to the present invention is formed by a CVD method. More specifically, a general CVD layer such as plasma CVD or thermal CVD can be used, and preferably SiH ₄ (monosilane). And N ₂ O (reducing agent). However, in the SiO ₂ layer 8 according to the present invention, it is necessary to adjust the film formation conditions such as the N ₂ O ratio, gas pressure, and film formation time so that the element ratio of N is 2%.

The thickness of the SiO ₂ layer 8 is preferably 1 μm or more, more preferably 2 to 10 μm, in view of the effect of preventing the diffusion of Na from the substrate 1. Since the influence of the base (the surface of the substrate 1) is likely to occur in this film thickness range, the SiO ₂ layer 8 desirably has an average surface roughness Ra of 4 nm or less. If Ra exceeds 4 nm, in the forming process (forming process of the first gap 5) and the activation process (forming process of the carbon film 6) in the element forming process, the conductive film 4 is affected by the roughness of the base. The resistance value becomes large, which may affect the formation of a good element.

As a material of the device electrodes 2 and 3, a general conductor material can be used. For example Ni, Cr, Au, Mo, W, Pt, Ti, Al, Cu, metal or alloy and Pd such as Pd, Ag, Au, RuO _2, metal or metal oxide such as Pd-Ag and glass, etc. A printed conductor is used. Further, a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor conductor material such as polysilicon are also used.

  The element electrode interval L and the element electrode length W are designed in consideration of the applied form and the like. The element electrode interval L can be preferably in the range of several hundred nm to several hundred μm, and more preferably several μm to several tens μm in consideration of the voltage applied between the element electrodes 2 and 3. It can be a range. The element electrode length W can be in the range of several μm to several hundred μm in consideration of the resistance value of the electrode and electron emission characteristics. The film thickness d of the device electrodes 2 and 3 can be in the range of several tens of nm to several μm.

Examples of the material of the conductive film 4 include metals such as Pd, Pt, Ru, Ag, Au, Ti, In, Cu, Cr, Fe, Zn, Sn, Ta, W, and Pb, PdO, SnO ₂ , and In ₂ O. ₃ , oxides such as PbO, Sb ₂ O ₃ and RuO ₂ are used. _{Further, HfB 2, ZrB 2, LaB} 6, CeB 6, YB 4, GdB borides such as _{4, TiC, ZrC, HfC,} TaC, SiC, and WC, etc., TiN, ZrN, nitrides such as HfN, Si , Semiconductors such as Ge, carbon and the like. Further, in order to control the resistance value of the material, it is possible to mix SiO ₂ or a metal oxide.

The conductive film 4 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. Further, the film thickness is appropriately set depending on the resistance value of the conductive film 4 and energization forming conditions described later, but is preferably 10 to 500 mm, particularly preferably 10 to 100 mm, and the sheet resistance value is Preferably, it is 10 ^{3 to} 10 ⁷ Ω / □.

  The fine particle film described here is a film in which a plurality of fine particles are aggregated, and the fine structure thereof is not only in a state where the fine particles are individually dispersed and arranged, but also in a state where the fine particles are adjacent or overlap each other (including island shapes). ), And the particle diameter of the fine particles is 10 to 200 mm.

  Next, a method for manufacturing the electron-emitting device of the present invention will be described with reference to FIG. 2, taking as an example the case of manufacturing the device shown in FIG. In FIG. 2, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG.

<Process 1>
The substrate 1 is sufficiently washed with a detergent, pure water, an organic solvent or the like, and the SiO ₂ layer 8 is laminated by the CVD method to form the substrate 10 [FIG. 2 (a)].

<Process 2>
After the device electrode material is deposited by vacuum deposition, sputtering, or the like, device electrodes 2 and 3 are formed on the substrate 1 by using, for example, a photolithography technique [FIG. 2 (b)].

  Next, the conductive film 4 is formed between the device electrodes 2 and 3 on the substrate 10. As a method for forming the conductive film 4, a sputtering method, a vacuum deposition method, a CVD method, a spinner method, or the like can be used, but the method is not limited thereto. Further, for example, a method in which a metal-containing solution is applied and heated by an inkjet method can also be used [FIG. 2 (c)].

<Process 3>
Next, a gap 5 is formed in the conductive film 4. Here, an example in which a process called “energization forming” is performed will be described.

  When power is supplied from a power source (not shown) between the device electrodes 2 and 3 under a predetermined degree of vacuum, a first gap (crack) 5 having a changed structure is formed in the conductive film 4 [FIG. ]. Although electron emission occurs from the vicinity of the gap 5 formed by this forming under a predetermined voltage, the electron emission efficiency is still very low under the current conditions.

  An example of the voltage waveform of energization forming is shown in FIG. The voltage waveform is particularly preferably a pulse waveform. For this purpose, there are a method shown in FIG. 3A in which a pulse having a pulse peak value as a constant voltage is continuously applied, and a method shown in FIG. 3B in which a pulse is applied while increasing the pulse peak value. is there.

  First, the case where the pulse peak value is a constant voltage will be described with reference to FIG. T1 and T2 in FIG. 3A are the pulse width and pulse interval of the voltage waveform. Usually, T1 is set in the range of 1 μsec to 10 msec, and T2 is set in the range of 10 μsec to 100 msec. The peak value of the triangular wave (peak voltage during energization forming) is appropriately selected according to the form of the electron-emitting device. Under such conditions, for example, a voltage is applied for several seconds to several tens of minutes. The pulse waveform is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted.

  Next, the case where a voltage pulse is applied while increasing the pulse peak value will be described with reference to FIG. T1 and T2 in FIG. 3B can be the same as those shown in FIG. The peak value of the triangular wave (peak voltage during energization forming) can be increased by, for example, about 0.1 V step.

  The end of the energization forming process can be completed when the resistance value is obtained by measuring the current flowing through the element to which the pulse voltage is applied, and the energization forming can be terminated when a resistance of, for example, 1 MΩ or more is indicated.

<Step 4>
As described above, the electron emission efficiency is very low in the state after forming. Therefore, in order to increase the electron emission efficiency, it is desirable to perform a process called activation on the element.

  In the activation treatment, carbon or a carbon compound is formed on the conductive film 4 by repeatedly applying a pulse voltage between the device electrodes 2 and 3 under an appropriate vacuum degree in an atmosphere containing a carbon-containing gas. The carbon film 6 is deposited in the vicinity of the first gap 5 [FIG. 2 (e)]. The carbon film 6 is deposited on the end of the conductive film 4 facing the first gap and in the first gap. Therefore, as shown in FIG. 2 (e), the carbon films 6 and 6 connected to the device electrodes 2 and 3 through the conductive films 4 and 4, respectively, are arranged to face each other through the second gap 7.

  In the electron-emitting device of the present invention, when a predetermined driving voltage is applied between the device electrodes 2 and 3, electrons are emitted from the carbon film 6.

In this step, an organic compound is used as the carbon source. For example, tolunitrile is used and introduced into the vacuum space through a slow leak valve to maintain about 1.3 × 10 ⁻⁴ Pa. The pressure of tolunitrile to be introduced is slightly affected by the shape of the vacuum apparatus and the members used in the vacuum apparatus, but is preferably about 1 × 10 ⁻⁵ Pa to 1 × 10 ⁻² Pa.

  FIG. 4 shows a preferred example of voltage application used in the activation process. The maximum voltage value to be applied is appropriately selected in the range of 10 to 20V.

  In FIG. 4A, T1 is the positive and negative pulse width of the voltage waveform, T2 is the pulse interval, and the voltage value is set to be equal in absolute value of positive and negative. In FIG. 4B, T1 and T1 ′ are the positive and negative pulse widths of the voltage waveform, T2 is the pulse interval, and T1> T1 ′, and the voltage value is set to be equal in absolute value of positive and negative. ing.

  In this step, the energization is stopped when the emission current Ie reaches almost saturation, the slow leak valve is closed, and the activation process is terminated.

  Through the above steps, the electron-emitting device as shown in FIG. 1 can be manufactured.

  The electron emission characteristics of the electron-emitting device of the present invention can be measured using a measurement evaluation apparatus shown in FIG.

  FIG. 5 is a schematic diagram of such a measurement evaluation apparatus, in which 21 is a power source for applying an element voltage Vf to the element, 20 is an ammeter for measuring the element current If flowing through the electrode part of the element, and 24. Is an anode electrode for capturing the emission current Ie emitted from the electron emission portion of the device. Reference numeral 23 denotes a high voltage power source for applying a voltage to the anode electrode 24, and reference numeral 22 denotes an ammeter for measuring the emission current Ie emitted from the element.

  In measuring the device current If flowing between the device electrodes 2 and 3 of the electron-emitting device and the emission current Ie to the anode, a power source 21 and an ammeter 20 are connected between the device electrodes 2 and 3, and the electron-emitting device An anode electrode 24 to which a power source 23 and an ammeter 22 are connected is disposed above the electrode.

  In addition, the electron-emitting device and the anode electrode 24 are installed in a vacuum device 25, and the vacuum device includes equipment necessary for the vacuum device such as an exhaust pump 26 and a vacuum gauge. The device can be measured and evaluated. The voltage of the anode electrode 24 is 1 kV to 10 kV, and the distance H between the anode electrode 24 and the electron-emitting device is measured in the range of 2 mm to 8 mm.

  FIG. 6 shows a typical example of the relationship between the emission current Ie and device current If measured by the measurement evaluation apparatus shown in FIG. 5 and the device voltage Vf. Although the emission current Ie and the device current If are remarkably different in magnitude, in FIG. 6, the vertical axis is expressed in arbitrary units on a linear scale for qualitative comparison of changes in If and Ie.

  This electron-emitting device has three characteristics with respect to the emission current Ie.

  First, as is apparent from FIG. 6, when an element voltage higher than a certain voltage (referred to as a threshold voltage, Vth in FIG. 6) is applied to this element, the emission current Ie increases rapidly. The emission current Ie is hardly detected below the threshold voltage Vth. That is, it can be seen that the characteristics as a non-linear element having a clear threshold voltage Vth with respect to the emission current Ie are shown.

  Second, since the emission current Ie depends on the element voltage Vf, the emission current Ie can be controlled by the element voltage Vf.

  Thirdly, the emitted charge captured by the anode electrode 24 depends on the time during which the device voltage Vf is applied. That is, the amount of charge trapped by the anode electrode 24 can be controlled by the time during which the device voltage Vf is applied.

  The atmosphere during driving of the electron-emitting device of the present invention is preferably maintained at the end of the stabilization step. However, if the organic substance is sufficiently removed, sufficiently stable characteristics can be maintained even if the pressure itself increases somewhat. By adopting such a vacuum atmosphere, it is possible to suppress the deposition of new carbon or a carbon compound on the electron-emitting device or the surface of the substrate 1 around the electron-emitting device. As a result, the device current If and the emission current Ie are reduced. ,Stabilize.

  Next, an example in which a plurality of electron-emitting devices of the present invention are arranged on a substrate to constitute an electron source and an image display device will be described.

  Various arrangements of the electron-emitting devices can be employed. As an example, a matrix arrangement schematically shown in FIG. 7 can be employed.

  In FIG. 7, 31 is a substrate, 32 is an X direction wiring, and 33 is a Y direction wiring. Reference numeral 34 denotes an electron-emitting device. The substrate 31 corresponds to the substrate 10 shown in FIG.

  The m X-direction wirings 32 are made of Dx1, Dx2,... Dxm, and can be made of a conductive metal or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. The wiring material, film thickness, and width are appropriately designed. The Y-direction wiring 33 is composed of n wirings Dy1, Dy2,... Dyn, and is formed in the same manner as the X-direction wiring 32. An interlayer insulating layer (not shown) is provided between the m X-direction wirings 32 and the n Y-direction wirings 33 to electrically isolate both (m and n are both Positive integer).

The interlayer insulating layer (not shown) is made of SiO ₂ , insulating metal oxide, a mixture thereof, or the like formed by using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, it is formed in a desired shape on the entire surface or a part of the substrate 31 on which the X-direction wiring 32 is formed. The manufacturing method is appropriately set. The X direction wiring 32 and the Y direction wiring 33 are respectively drawn out as external terminals.

  The aforementioned pair of electrodes 2 and 3 constituting the electron-emitting device 34 are electrically connected to m X-direction wirings 32 and n Y-direction wirings 33, respectively.

  The material constituting the wiring 32 and the wiring 33 and the material constituting the pair of electrodes 2 and 3 may be the same or partially different from each other. These materials are appropriately selected from, for example, the electrode materials described above. When the material constituting the electrode and the wiring material are the same, the wiring connected to the electrode can also be called an electrode.

  The X direction wiring 32 is connected to a scanning signal applying means (not shown) for applying a scanning signal for selecting a row of the electron-emitting devices 34 arranged in the X direction. On the other hand, the Y-direction wiring 33 is connected to modulation signal generating means (not shown) for modulating each column of the electron-emitting devices 34 arranged in the Y direction according to an input signal. 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 and driven independently using a simple matrix wiring.

  The method for manufacturing an electron source according to the present invention is basically the same as the method for manufacturing an electron-emitting device described above, except that a plurality of electron-emitting devices are simultaneously formed on the same substrate and wiring is formed.

  An image display device configured using such a simple matrix electron source will be described with reference to FIGS. FIG. 8 is a schematic diagram illustrating an example of a display panel of the image display apparatus.

  In FIG. 8, 31 is an electron source substrate shown in FIG. 7, 42 is a face plate (second film) in which a fluorescent film 44 as a light emitter that emits light upon irradiation of electrons and a metal back 45 are formed on the inner surface of a glass substrate 43. 46) is a support frame. The electron source substrate 31, the support frame 46, and the face plate 42 are bonded with frit glass, and baked at 400 to 500 ° C. for 10 minutes or more to be sealed to form the envelope 47.

  In addition, by installing a support body (not shown) called a spacer between the face plate 42 and the electron source substrate 31, an envelope 47 having sufficient strength against atmospheric pressure even in the case of a large area panel. Can also be configured.

  FIG. 9 is an explanatory diagram of the fluorescent film 44 provided on the face plate 42. In the case of a monochrome film, the fluorescent film 44 is composed only of a fluorescent material. In the case of a color fluorescent film, the fluorescent film 44 is composed of a black conductor 51 and a fluorescent material 52 called a black stripe or a black matrix depending on the arrangement of the fluorescent materials. . The purpose of providing the black stripes and the black matrix is to make the mixed colors and the like inconspicuous by making the color-separated portion between the phosphors 52 of the three primary color phosphors necessary for color display black. In addition, a decrease in contrast due to reflection of external light in the fluorescent film 44 is suppressed.

  A metal back 45 is usually provided on the inner surface side of the fluorescent film 44. The purpose of the metal back is to improve the brightness by specularly reflecting the light emitted from the phosphor toward the inner surface to the face plate 42 side, to act as an anode electrode for applying an electron beam acceleration voltage, etc. It is. The metal back can be manufactured by performing a smoothing process (usually called filming) on the inner surface of the fluorescent film after manufacturing the fluorescent film, and then depositing Al by vacuum evaporation or the like.

  When performing the above-mentioned sealing, in the case of a color, each color phosphor must correspond to the electron-emitting device, so that it is necessary to perform sufficient alignment by a method of abutting the upper and lower substrates.

The degree of vacuum at the time of sealing is required to be about 10 ⁻⁵ Pa, and in order to maintain the degree of vacuum after the envelope 47 is sealed, getter processing may be performed. This is because the getter disposed at a predetermined position (not shown) in the envelope 47 is heated by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 47 is sealed. This is a process for forming a deposited film. The getter usually contains Ba or the like as a main component, and maintains the degree of vacuum by the adsorption action of the deposited film.

  According to the basic characteristics of the electron-emitting device described above, electrons emitted from the electron-emitting device are controlled by the peak value and width of the pulse voltage applied between the opposing electrodes above the threshold voltage. The amount of current is also controlled by the value, so that halftone display is possible.

  In addition, in an electron source in which a large number of electron-emitting devices are arranged, if a selection line is determined by a scanning line signal of each line and the pulse voltage is appropriately applied to each element through each information signal line, an appropriate element can be appropriately selected. Each element can be turned on by applying a voltage.

  Examples of a method for modulating the electron-emitting device according to an input signal having a halftone include a voltage modulation method and a pulse width modulation method.

  A specific drive device will be described below.

  FIG. 10 shows a configuration example of an image display device for television display based on NTSC television signals using a display panel configured using an electron source substrate having a simple matrix arrangement.

  10, 61 is an image display panel as shown in FIG. 8, 62 is a scanning circuit, 63 is a control circuit, 64 is a shift register, 65 is a line memory, 66 is a synchronizing signal separation circuit, and 67 is an information signal generator. Va is a DC voltage source.

  An X driver scanning circuit 62 that applies a scanning line signal to the X direction wiring of the image display panel 61 using the electron source substrate 31 and a Y driver information signal generator 67 that applies an information signal to the Y wiring. Is connected.

  In order to implement the voltage modulation method, the information signal generator 67 uses a circuit that generates a voltage pulse of a certain length but appropriately modulates the peak value of the pulse according to input data. In order to implement the pulse width modulation system, the information signal generator 67 generates a voltage pulse having a constant peak value, but appropriately modulates the width of the voltage pulse according to input data. Is used.

  The control circuit 63 generates Tscan, Tsft, and Tmry control signals for each unit based on the synchronization signal Tsync sent from the synchronization signal separation circuit 66.

  The synchronization signal separation circuit 66 is a circuit for separating a synchronization signal component and a luminance signal component from an NTSC television signal input from the outside. This luminance signal component is input to the shift register 64 in synchronization with the synchronization signal.

  The shift register 64 performs serial / parallel conversion on the luminance signal input serially in time series for each line of the image, and operates based on the shift clock Tsft sent from the control circuit 63. Data for one line of the image subjected to serial / parallel conversion (corresponding to driving data for n electron-emitting devices) is output from the shift register 64 as n parallel signals.

  The line memory 65 is a storage device for storing data for one line of the image for a necessary time, and the stored contents are input to the information signal generator 67.

  The information signal generator 67 is a signal source for appropriately driving each electron-emitting device according to each luminance signal. The output signal enters the display panel 61 through the Y direction wiring, and is applied to each electron-emitting device at the intersection with the selected X direction wiring by the scanning circuit 62.

  By sequentially scanning the X-direction wiring, it becomes possible to drive the electron-emitting devices on the entire surface of the panel.

  As described above, in the image display device of the present invention, electrons are emitted by applying a voltage to each electron-emitting device through the XY-directional wiring. On the other hand, an image is displayed by applying a high voltage to the metal back 45 which is an anode electrode through a high voltage terminal Hv connected to the DC voltage source Va, accelerating the generated electron beam and causing it to collide with the fluorescent film 44. Can do.

  The configuration of the image display device described here is an example of the image display device of the present invention, and various modifications can be made based on the technical idea of the present invention. Although the NTSC system is used for the input signal, the input signal is not limited to this, and the same applies to PAL, HDTV, and the like.

  Hereinafter, the present invention will be described in detail with specific examples. Although the CVD apparatus used in the present invention is an apparatus corresponding to a maximum G5 size substrate, it is not limited to these examples, and each element replacement or design change within a range in which the object of the present invention is achieved. Also included are those made.

Example 1
<Formation of SiO ₂ layer>
A SiO ₂ film was formed on a glass substrate (base) having a size of 300 × 350 mm and a thickness of 1.8 mm under the following conditions.

Reaction gas: SiH ₄ = 1000 sccm, N ₂ O = 20000 sccm
Gas pressure: 80 Pa (0.6 torr)
Substrate temperature: 350 ° C
RF frequency: 13.56 MHz
Deposition time: 5 min

When the film thickness of the obtained SiO ₂ layer was measured with a step stylus measuring machine, it was 1.20 μm. The composition of the film was XPS (X-ray photoelectron spectrometer), and the element ratio of N was 1%. An image display device was produced using this substrate. The manufacturing process of the electron source is shown in FIGS.

<Formation of device electrode>
An aqueous solution of a metal organic compound and an aqueous solution of a resin (polyvinyl alcohol) containing a photosensitizer (sodium 4,4′-diazidostilbene-2,2′-disulfonate) are mixed in the following ratio to prepare a composition. did.
Metal organic compound: 50 parts by mass [tetrakis (monoethanolamino) platinum (II) acetate, platinum content 5% by mass]
Resin: 50 parts by mass (including 10 parts by mass of photosensitive agent)

This composition was applied to the entire surface of the substrate 31 on which the SiO ₂ layer was laminated with a slit coater, dried at 133 Pa (1 torr) for 60 seconds with a vacuum dryer, and further dried at 80 ° C. for 10 minutes with a hot plate. The thickness of the coating film after drying was 2.05 μm.

Next, using a negative photomask, the region for forming the device electrodes 2 and 3 was exposed with an ultrahigh pressure mercury lamp (illuminance = 20 mW / cm ² ) with a gap of 100 μm and an exposure time of 10 seconds. After the exposure, pure water was used as a developer and the film was processed by dipping for 30 seconds to obtain a coating film in which the electrode region was patterned. This was put into a hot air circulating furnace and baked at 520 ° C. for 1 hour. Thereby, element electrodes 2 and 3 made of a platinum thin film were formed (FIG. 11).

  The element electrode in this example was configured such that an electrode 3 having a width of 60 μm and a length of 480 μm and an electrode 2 having a width of 120 μm and a length of 200 μm were opposed to each other with an interelectrode gap of 20 μm (L in FIG. 1). The pitch of the element electrode pairs was 300 μm in the horizontal direction and 650 μm in the vertical direction, and the number of element electrode pairs was 720 × 240 and arranged in a matrix.

<Formation of lower wiring>
The Y-direction wiring (lower wiring) 33 as a common wiring was formed in a line pattern so as to be in contact with one element electrode 2 and to connect them. The material was Ag photo paste ink, screen printed, dried, exposed to a predetermined pattern and developed. Thereafter, the Y-direction wiring 33 was formed by baking at a temperature of about 480 ° C. (FIG. 12). The Y-direction wiring 33 has a thickness of about 10 μm and a width of about 50 μm. In addition, since the termination | terminus part was used as a wiring extraction electrode, line | wire width was enlarged more.

<Formation of insulating layer>
An insulating layer 71 was formed to insulate the upper and lower wirings. An X-direction wiring 32 and the other element electrode 3 can be electrically connected so as to cover an intersection with the previously formed Y-direction wiring 33 under an X-direction wiring (upper wiring) 32 described later. Then, a contact hole was formed in the connection part (FIG. 13).

Specifically, a photosensitive glass paste mainly composed of Bi ₂ O ₃ was screen-printed and then exposed and developed. This was repeated four times, and finally fired at a temperature of around 500 ° C. The insulating layer 71 has a total thickness of about 30 μm and a width of 150 μm.

<Formation of upper wiring>
On the insulating layer 71 formed earlier, Ag paste ink is screen-printed and dried, printed again in the same manner, applied twice, and then baked at a temperature of about 480 ° C. in the X direction. A wiring (upper wiring) 32 was formed (FIG. 14). The X-direction wiring 32 intersects the Y-direction wiring 33 with the insulating layer 71 interposed therebetween, and is connected to the electrode 3 at the contact hole portion of the insulating layer 71. The thickness of the X direction wiring 32 is about 15 μm. Although not shown, the extraction electrode portion to the external drive circuit was also formed by the same method.

  In this way, the plurality of element electrodes 2 and 3 formed on the substrate 31 were connected by XY matrix wiring.

<Conductive film formation process>
The substrate was washed with pure water. A palladium acetate-monoethanolamine complex is dissolved in an aqueous solution in which 0.05% by mass of polyvinyl alcohol, 15% by mass of 2-propanol and 1% by mass of ethylene glycol are dissolved so that palladium is about 0.15% by mass. As a result, a pale yellow aqueous solution was obtained. The droplet of this aqueous solution was applied to the same portion four times by an ink jet method so as to be applied over the electrode gap between the device electrodes 2 and 3 from the device electrodes 2 and 3 forming each device electrode pair. (Dot diameter = about 100 μm).

  The substrate 31 provided with the aqueous solution droplets was baked in a baking furnace at 350 ° C. for 30 minutes, and the conductive film 4 made of palladium was formed between each element electrode pair to connect the element electrodes 2 and 3. (FIG. 15).

<Forming process>
Next, a hood-like lid was put on the substrate 31 so as to cover the entire substrate, leaving a take-out electrode portion around the substrate 31, and a vacuum space was created inside the substrate 31. In this state, the conductive film 4 is locally destroyed, deformed, or altered by applying a voltage from the electrode terminal portion to the XY direction wirings 32, 33 from the external power source and energizing the element electrodes 2, 3. As a result, a gap 5 was formed.

  The voltage waveform used for the forming process was a rectangular pulse waveform as shown in FIG. 3B, and T1 was 0.1 msec and T2 was 50 msec. The applied voltage was started from 0.1V and increased by about 0.1V step every 5 seconds. The end of the energization forming process was completed when the resistance value was determined by measuring the current flowing through the element when the pulse voltage was applied, and the energization forming was terminated.

<Activation process>
In the same manner as the above forming, a hood-like lid is covered to create a vacuum space between the substrate 31 and trinitrile as a carbon source is introduced into the vacuum space through a slow leak valve, and 1.3 × 10 ^−4. Pa was maintained and the activation process was performed.

  As the pulse, 18 V, 1 ms short pulse and -18 V, 1 ms short pulse were alternately applied at 100 Hz. After about 60 minutes, when the emission current Ie reached almost saturation, the energization was stopped, the slow leak valve was closed, and the activation process was completed.

  Through the above steps, an electron source in which a large number of electron-emitting devices are connected on a substrate on a matrix wiring can be manufactured.

  The display panel shown in FIG. 8 is manufactured using the electron source of the simple matrix arrangement manufactured as described above, and the drive circuit including the scanning circuit, the control circuit, the modulation circuit, the DC voltage source, etc. of FIG. 10 is connected, A panel-shaped image display device was manufactured.

  An arbitrary matrix image pattern is driven by applying a predetermined voltage in a time-sharing manner to each electron-emitting device through the X-direction terminal and the Y-direction terminal, and applying a high voltage to the metal back 45 through the high-voltage terminal 48. Could be displayed with good image quality.

(Example 2)
<Formation of SiO ₂ layer>
An SiO ₂ layer was formed on a glass substrate (base) having a size of 300 × 350 mm and a thickness of 1.8 mm under the following conditions.
Reaction gas: SiH ₄ = 5000 sccm, N ₂ O = 50000 sccm
Gas pressure: 267 Pa (2.0 torr)
Substrate temperature: 350 ° C
RF frequency: 13.56 MHz
Deposition time: 1.5 min

The thickness of the obtained SiO ₂ layer was measured with a step stylus measuring machine and found to be 1.50 μm. The composition of the film was XPS (X-ray photoelectron spectrometer), and the N element ratio was 2%. Using this substrate 31, an image display device was produced in exactly the same manner as in Example 1.

  An arbitrary matrix is applied by applying a predetermined voltage to each electron-emitting device in a time-sharing manner through the X-direction terminal and the Y-direction terminal of the obtained image display device, and applying a high voltage to the metal back 45 through the high-voltage terminal 48. The image pattern was driven. As a result, it was possible to display with good image quality.

(Comparative Example 1)
<Formation of SiO ₂ layer>
An SiO ₂ layer was formed on a glass substrate (base) having a size of 300 × 350 mm and a thickness of 1.8 mm under the following conditions.
Reaction gas: SiH ₄ = 6250 sccm, N ₂ O = 50000 sccm
Gas pressure: 267 Pa (2.0 torr)
Substrate temperature: 350 ° C
RF frequency: 13.56 MHz
Deposition time: 1 min

The thickness of the resulting SiO ₂ layer was measured at the step stylus measuring instrument and found to be 1.35 .mu.m. The composition of the film was XPS (X-ray photoelectron spectrometer), and the element ratio of N was 3%. Using this substrate, an image display device was produced in exactly the same manner as in Example 1.

  However, the emission current Ie did not reach saturation in some devices during the activation process. By applying a predetermined voltage to each electron-emitting device in a time-sharing manner through the X-direction terminal and the Y-direction terminal of the obtained device and applying a high voltage to the metal back 45 through the high-voltage terminal 48, an arbitrary matrix image pattern is obtained. Was driven. As a result, it was impossible to display an image as good as that of the example due to the presence of an element that was not sufficiently activated.

(Comparative Example 2)
<Formation of SiO ₂ layer>
An SiO ₂ layer was formed on a glass substrate (base) having a size of 300 × 350 mm and a thickness of 1.8 mm under the following conditions.
Reaction gas: SiH ₄ = 5000 sccm, N ₂ O = 20000 sccm
Gas pressure: 200 Pa (1.5 torr)
Substrate temperature: 350 ° C
RF frequency: 13.56 MHz
Deposition time: 1 min

When the film thickness of the obtained SiO ₂ layer was measured with a step stylus measuring machine, it was 1.20 μm. The composition of the film was XPS (X-ray photoelectron spectrometer), and the N element ratio was 9%. Using this substrate, an image display device was produced in exactly the same manner as in Example 1.

  However, the emission current Ie did not reach saturation in some devices during the activation process. By applying a predetermined voltage to each electron-emitting device in a time-sharing manner through the X-direction terminal and the Y-direction terminal of the obtained device and applying a high voltage to the metal back 45 through the high-voltage terminal 48, an arbitrary matrix image pattern is obtained. Was driven. As a result, it was impossible to display an image as good as that of the example due to the presence of an element that was not sufficiently activated.

It is a schematic diagram which shows the structure of one Embodiment of the electron emission element of this invention. It is a schematic diagram which shows the manufacturing process of the electron emission element of FIG. It is a figure which shows the voltage waveform used for the energization forming process in the manufacturing method of the electron-emitting element of this invention. It is a figure which shows the voltage waveform used for the activation process in the manufacturing method of the electron emission element of this invention. It is the schematic which shows the structure of the measurement evaluation apparatus of the electron emission characteristic of the electron emission element of this invention. It is a figure which shows the emission characteristic of the electron-emitting device of this invention. It is a schematic diagram which shows the structural example of the electron source of this invention. It is a perspective view which shows typically the structure of the display panel of an example of the image display apparatus of this invention. It is a figure which shows typically the structure of the fluorescent film used for the image display apparatus of this invention. It is a figure which shows the structural example of the image display apparatus for television displays. It is a figure which shows the manufacturing process of the electron source in the Example of this invention. It is a figure which shows the manufacturing process of the electron source in the Example of this invention. It is a figure which shows the manufacturing process of the electron source in the Example of this invention. It is a figure which shows the manufacturing process of the electron source in the Example of this invention. It is a figure which shows the manufacturing process of the electron source in the Example of this invention. It is a figure which shows the manufacturing process of the electron source in the Example of this invention.

Explanation of symbols

1 substrate 2,3 device electrodes 4 conductive film 5 first gap 6 carbon film 7 second gap 8 SiO ₂ layer 10 substrate

Claims (7)

An electron comprising a pair of element electrodes on a substrate, a conductive film having a first gap formed between the element electrodes, and a carbon film having a second gap in at least the first gap A method for manufacturing an emitting device, comprising:
Forming a layer mainly composed of SiO ₂ on a substrate by a CVD method to form a substrate;
Forming a pair of device electrodes on the substrate;
Forming a conductive film between the element electrodes;
Forming a first gap in the conductive film;
Forming a carbon film having a second gap by applying a voltage between the pair of device electrodes in an atmosphere containing a carbon-containing gas;
Have
A method for manufacturing an electron-emitting device, wherein the element ratio of N in the layer mainly composed of SiO ₂ is 2% or less. A method of manufacturing an electron-emitting device according to claim 1, the layer mainly containing the SiO _2, is formed by a CVD method using SiH ₄ and N ₂ O. An electron-emitting device comprising: a pair of device electrodes; a conductive film having a first gap formed between the device electrodes; and a carbon film having a second gap at least in the first gap. A method of manufacturing a plurality of electron sources on a substrate,
Forming a layer mainly composed of SiO ₂ on a substrate by a CVD method to form a substrate;
Forming a plurality of device electrode pairs on the substrate;
In each element electrode pair, forming a conductive film between the element electrodes;
Forming a first gap in the conductive film;
Forming a carbon film having a second gap by applying a voltage between the pair of device electrodes in an atmosphere containing a carbon-containing gas;
Have
A method for producing an electron source, wherein the element ratio of N in the layer mainly composed of SiO ₂ is 2% or less. Wherein a layer mainly composed of SiO _2, method of manufacturing an electron source according to claim 3 which is formed by a CVD method using SiH ₄ and N ₂ O. An electron comprising a pair of element electrodes on a substrate, a conductive film having a first gap formed between the element electrodes, and a carbon film having a second gap in at least the first gap An emission element,
An electron-emitting device, wherein the substrate is a layer mainly composed of SiO ₂ formed on a substrate by a CVD method, and an element ratio of N is 2% or less.   An electron source having a plurality of electron-emitting devices on a substrate, wherein the electron-emitting device is the electron-emitting device according to claim 5.   7. The electron source according to claim 6 and a second substrate on which a light emitter that emits light by irradiation of electrons emitted from the electron-emitting device is opposed to the electron-emitting device of the electron source. An image display device characterized by comprising:

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