JP2011187278A - Electron emission element, and electron source substrate and image display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron emission element which can achieve both an increase of an electron emission current and focusing of a beam diameter simultaneously. <P>SOLUTION: A first low potential side electrode 4 is arranged on a first side surface 21 of a first insulation layer 2, a first high potential side electrode 5 is arranged on a second side surface 22, and a second low potential side electrode 6 is arranged on the first insulation layer 2 through a second insulation layer 3. In addition, a second high potential side electrode 8 is arranged on the low potential side electrode 6 through a third insulation layer 7. Electrons are emitted from a gap 9 between the first low potential side electrode 4 and the second high potential side electrode 8, and a gap 10 between the first high potential side electrode 5 and the second low potential side electrode 6, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image display device used for a flat panel display, and an electron source substrate and an electron-emitting device constituting the image display device.

  Conventionally, there are electron-emitting devices in which a large number of electrons emitted from a low-potential side electrode are taken out as electrons after colliding with and scattering the opposed high-potential side electrode. As devices that emit electrons in such a form, surface conduction electron-emitting devices and stacked electron-emitting devices are known. For example, Patent Documents 1 and 2 disclose an electron-emitting device formed by laminating a low-potential side electrode, an insulating layer, and a high-potential side electrode, and by providing electron emitting portions on both sides of the high-potential side electrode. The electron emission current is increased.

JP 2000-311587 A US Pat. No. 6,288,494

  However, in the electron-emitting device disclosed in Patent Document 1, electrons emitted from the electron-emitting portions provided on both sides of the high potential side electrode are emitted in the opposite direction toward the anode. Therefore, depending on the width of the high potential side electrode (distance between the electron emission portions), the beam diameter is widened, which is problematic for application to a high-definition display. An object of the present invention is to provide an electron-emitting device that can simultaneously increase an electron-emitting current and focus a beam diameter, and to provide a high-definition and high-quality image display device.

The first aspect of the present invention has an upper surface and first and second side surfaces sandwiching the upper surface, the first concave portion at the upper surface side end portion of the first side surface, and the upper surface side of the second side surface A first insulating member having a second recess at an end thereof,
A first low potential side electrode disposed on the first side and having one end along the edge of the first recess;
A first high-potential side electrode disposed on the second side surface and having one end along the edge of the second recess;
A first side surface having a third side surface at a position retracted inward from the first concave portion, and a fourth side surface that coincides with an extended surface of the second side surface; A second low-potential side electrode disposed on the upper surface of the member and facing the first high-potential side electrode via the second recess;
A fifth side surface at a position retracted inward from the first recess, a sixth side surface at a position retracted inward from the fourth side surface, and a second side of the second low potential side electrode. A second insulating member disposed on the second low-potential side electrode so as to cover the side surface of the second low-potential side electrode;
The first insulating member has a seventh side surface that coincides with the extended surface of the first side surface, and faces the first low potential side electrode through the first recess. And a second high potential side electrode disposed on the second insulating member;
It is an electron emission element characterized by having.

  A second aspect of the present invention is an electron source substrate comprising a substrate, a plurality of electron-emitting devices disposed on the substrate, and wiring for applying a voltage to the electron-emitting devices, The device is the electron-emitting device of the present invention.

According to a third aspect of the present invention, the electron source substrate of the present invention,
An anode disposed opposite to the first low potential side electrode and the first high potential side electrode with a second high potential side electrode of the electron-emitting device formed on the electron source substrate interposed therebetween; A light emitting member that is disposed in a stacked manner and emits light by irradiation of electrons emitted from the electron emitter,
It is an image display apparatus characterized by having.

  According to the present invention, since electrons are emitted from two locations in the electron-emitting device, the electron emission current can be increased, and electrons emitted from the two locations fly in the same direction with respect to the anode. Therefore, it is possible to easily focus the beam diameter. Therefore, according to the present invention, an image display device with higher definition and higher image quality than before can be realized.

It is a figure which shows the structure of one Embodiment of the electron-emitting element of this invention, and the supply arrangement | positioning of a power supply when measuring the electron emission characteristic. It is a figure which shows the mode of the electron emission in the conventional multilayer electron emission element, and the light emission pattern of the light emission member by this element. It is a figure which shows the mode of the electron emission in the electron emission element which has arrange | positioned the low potential side electrode to the anode side rather than the high potential side electrode, and the light emission pattern of the light emission member by this element. It is a figure which shows the mode of the electron emission in the electron emission element which has arrange | positioned the low potential side electrode to the anode side rather than the high potential side electrode, and the light emission pattern of the light emission member by this element. It is a figure which shows the mode of the electron emission in the electron emission element of this invention, and the light emission pattern of the light emission member by this element. It is a figure which shows the example of a manufacturing process of the electron emission element shown in FIG. It is a figure which shows the manufacturing process of the electron-emitting element of the comparative example produced in the Example of this invention. It is a figure which shows the structure of the electron source board | substrate which has multiple electron-emitting elements produced in the Example of this invention. 1 is a schematic diagram of an image display device of the present invention and an electron source substrate constituting the image display device.

  Hereinafter, exemplary embodiments of the present invention will be described in detail 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. .

[Configuration overview]
The electron-emitting device of the present invention includes first and second insulating members, first and second low potential side electrodes, and first and second high potential side electrodes. The electron source substrate of the present invention includes a plurality of the electron-emitting devices of the present invention arranged on a substrate and wiring for applying a voltage to the device. Furthermore, an image display device of the present invention includes an electron source substrate having the electron-emitting device of the present invention, an anode to which electrons emitted from the electron-emitting device reach, and a light-emitting member that emits light when irradiated with the electrons. ing.

  FIG. 1A is a schematic cross-sectional view showing the configuration of a preferred embodiment of the electron-emitting device of the present invention. In the figure, 1 is a substrate, 2 is a first insulating layer, 3 is a second insulating layer, and the combination of the first insulating layer 2 and the second insulating layer 3 is the first according to the present invention. It is an insulating member. In the present invention, since the formation is easy, the first insulating member is preferably formed by laminating the second insulating layer 3 on the first insulating layer 2, but the present invention is limited to this. It is not a thing. In the present invention, the first insulating member has first and second side surfaces 21 and 22 that are not in contact with each other, and the respective side surfaces are disposed at the end portions on the upper surface side sandwiched between the side surfaces. Two recesses 13 and 14 are provided. In FIG. 1A, the concave portions 13 and 14 are portions where the side surfaces of the second insulating layer 3 are recessed inward from the first and second side surfaces 21 and 22 of the first insulating layer 2.

  For convenience, the “side surface”, “upper surface”, and vertical relationship of each member according to the electron-emitting device of the present invention are defined on the assumption of the arrangement shown in FIG. In the arrangement, it is only necessary that the side surface, the upper surface, and the vertical relationship of each member satisfy the provisions of the present invention. Therefore, depending on the arrangement of the entire electron-emitting device, the “side surface” does not necessarily face in the horizontal direction and the “upper surface” does not face upward in the vertical direction. The case where the “upper surface” is directed horizontally or downward is also within the scope of the present invention.

  The first low potential side electrode 4 is disposed on the first side surface 21 of the first insulating layer 2, and the first high potential side electrode 5 is disposed on the second side surface 22. 14 along the edge. In FIG. 1A, the first side surface 21 is the left side surface of the first insulating layer 2, and the second side surface 22 is the right side surface of the first insulating layer 2. The second low potential side electrode 6 is disposed on the upper surface of the second insulating layer 2 that is the upper surface of the first insulating member, and one side surface (fourth side surface 24) thereof is the second side surface 22. Of the first high potential side electrode 5 through the second recess 14. In addition, the third side surface 23 of the second low potential side electrode 6 is in a position that is recessed inward from the side surface of the second insulating layer 3 (that is, the first recess 13).

  The third insulating layer 7 which is the second insulating member according to the present invention is disposed on the second low potential side electrode 6. One side surface (fifth side surface 25) of the third insulating layer 7 is in a position retracted inward from the first concave portion 13, and the other side surface (sixth side surface 26) is the second low potential side. The electrode 6 is in a position retracted inward from the fourth side surface 24. The third insulating layer 7 covers the third side surface 23 of the second low potential side electrode 6.

  The second high potential side electrode 8 is disposed on the second insulating layer 3 and the third insulating layer 7, and one side surface (seventh side surface 27) is the first of the first insulating layer 2. It is in the position which corresponds on the extended surface of the side surface 21 of this. The position of the other side surface (eighth side surface 28) is not particularly limited as long as a predetermined electric field to be described later can be formed. However, for ease of manufacturing, the fourth side surface of the second low potential side electrode 6 is used. It is preferred that they coincide on the 24 extended surfaces.

  In the electron-emitting device of the present invention, the gap 9 in which the distance between the first low potential side electrode 4 and the second high potential side electrode 8 is the shortest, the first high potential side electrode 5 and the second low potential side electrode 8 is the same. Electrons are emitted from the gap 10 having the shortest distance from the potential side electrode 6. Reference numerals 11 and 12 denote electrodes connected to the first low potential side electrode 4 and the first high potential side electrode 5, respectively.

  The image display device according to the present invention includes a first low potential side electrode 4, a first high potential side electrode 5, and a second high potential side electrode 8 interposed therebetween. An anode defined at a higher potential than the second high potential side electrode 8 is provided at the opposing position (20 in FIG. 1B). In this example, since the first insulating layer 2 is disposed on the substrate 1, the anode 20 is disposed opposite to the substrate 1 on the side where the first insulating layer 2 is disposed. It can be said that it is. In the image display device of the present invention, a light emitting member is laminated on the outside of the anode 20 (on the side opposite to the side where the electron-emitting device is located).

  FIG. 1B shows a power supply arrangement when measuring the electron emission characteristics of the electron-emitting device of the present invention. As shown in FIG. 1B, in the present invention, the anode 20 is disposed opposite to the substrate 1 on the side where the first insulating layer 2 of the substrate 1 is disposed. In FIG. 1B, Vf is a voltage applied between the first low potential side electrode 4 and the second high potential side electrode 8 with the first low potential side electrode 4 as the low potential side. Vf is also a voltage applied between the second low potential side electrode 6 and the first high potential side electrode 5 with the second low potential side electrode 6 as the low potential side. If is a device current that flows when Vf is applied. Va is a voltage applied between the first low potential side electrode 4 and the second low potential side electrode 6 and the anode 20 with the anode 20 as a high potential side, and Va> Vf. Ie is an electron emission current that flows when Va is applied. Here, the electron emission efficiency η = Ie / (If + Ie) is given by using the current If detected when a voltage is applied to the electron-emitting device and the current Ie taken out in vacuum.

  When a voltage Vf is applied to the electron-emitting device of the present invention as shown in FIG. 1B, in the gap 9 and the gap 10, the tips of the low-potential-side electrodes 4 and 6 face the high-potential-side electrodes 8 and 5, respectively. As a result, electrons tunnel, and the electrons are isotropically scattered on the surfaces of the high potential side electrodes 8 and 5. The electrons emitted from the low potential side electrodes 4 and 6 are repeatedly elastically scattered several times on the surfaces of the high potential side electrodes 8 and 5, and then accelerated by the voltage Va and directed toward the anode 20. The electrons heading from the gaps 9 and 10 toward the anode 20 reach the anode 20 while drawing a trajectory affected by the potential formed between the gaps 9 and 10 and the anode 20.

[Electron anode arrival position by electrode arrangement]
Here, the arrival position when the electrons emitted from the electron-emitting device reach the anode 20 will be described with reference to FIGS.

<Double-sided electron emission, forward polarity>
FIG. 2A shows the configuration of an image display device using a conventional stacked electron-emitting device. 36 is a low potential side electrode, 31 is a high potential side electrode, and 40 is a low potential side electrode. The connected electrodes 33 and 38 are gaps in which an electric field necessary for electron emission is formed. The gap 33 is a part where the distance between the low potential side electrode 36 and the high potential side electrode 31 is shortest, and the gap 38 is a part where the distance between the low potential side electrode 4 and the high potential side electrode 31 is shortest. In addition, the same code | symbol was attached | subjected to the same member as Fig.1 (a). Vf is a voltage applied between the low potential side electrodes 4 and 36 and the high potential side electrode 31, Va is a voltage applied between the low potential side electrodes 4 and 36 and the anode 20, and If is applied when Vf is applied. The flowing element current, Ie, is an electron emission current that flows when Va is applied. A broken line 34 is an equipotential line of an electric field formed when Vf and Va are applied, and 35 is a stagnation point described later. Although not shown, a light emitting member is disposed outside the anode 20 (on the side opposite to the side where the electron-emitting device is located).

  When a voltage Vf is applied between the low potential side electrodes 4 and 36 and the high potential side electrode 31 in FIG. 2A, electrons are emitted from the gaps 33 and 38. The emitted electrons travel toward the high potential side electrode 31 and are repeatedly scattered several times on the surface of the high potential side electrode 31. When the voltages Vf and Va are applied simultaneously, a point where an equipotential line corresponding to the potential of the high potential side electrode 31 intersects the surface of the high potential side electrode 31 is generated. This is the stagnation point 35.

  Here, consider the electrons emitted from the gap 33. After repeating scattering several times on the surface of the high potential side electrode 31, until it comes out of the equipotential line passing through the stagnation point 35 as viewed from the gap 33 (on the left side or the upper side in FIG. 2A). As shown in FIG. 2 (a), the velocity component is obtained by accelerating the horizontal direction left side as well. Electrons emitted outside the stagnation point 35 are accelerated by the voltage Va and reach the anode 20, but there is almost no horizontal electric field component in the meantime, so the horizontal direction component is directed to the left as seen in FIG. Almost constant speed movement. That is, the arrival position of the electrons emitted from the gap 33 at the anode 20 is shifted to the left side as viewed in FIG. Similarly, since the electrons emitted from the gap 38 can be considered to be opposite to the electrons emitted from the gap 33, the arrival position of the electrons emitted from the gap 38 at the anode 20 is more than just above the gap 38. The position is shifted to the right as viewed in FIG.

  The electrons that have reached the anode 20 cause the light emitting member disposed outside the anode 20 to emit light and display an image. FIG. 2B shows a light emission pattern of the light emitting member obtained by the electron-emitting device having the configuration shown in FIG. 2B, A is a region where electrons emitted from the gap 33 in FIG. 2A reach the anode 20 to emit light, and B is an electron emitted from the gap 38 in FIG. 2A. This is a region that reaches 20 and emits light. The outline of each region indicates a 10% range of peak luminance. Since the arrival positions of the electrons emitted from the gaps 33 and 38 in FIG. 2A in the anode 20 are shifted in the left and right reverse directions, the light emission patterns of A and B are also shown in FIG. It is displayed in two forms. The size Lx, Ly (beam diameter) of the contour line of the light emission pattern is estimated by simulation. When the vertical distance H = 1.6 mm, Va = 11.8 kV, and Vf = 23 V from the surface of the substrate 1 to the anode 20 in FIG. 2A, Lx = 250 μm and Ly = 230 μm. Further, in the configuration of FIG. 2A, the electron emission efficiency η = Ie / (If + Ie) is 5.5%.

  2A has the gaps 33 and 38 for emitting electrons on both sides of the high potential side electrode 31, the current (If, Ie) obtained is large. On the other hand, the anode arrival position of the electrons emitted from the gaps 33 and 38 is greatly shifted in the opposite direction, and the beam diameter at the anode 20 becomes wide, so that it can be applied to a high-definition display. Is inconvenient.

<One-sided electron emission, reverse polarity>
FIGS. 3A and 4A are schematic views of an image display device using a stacked electron-emitting device having a configuration in which a low potential side electrode is disposed above a high potential side electrode. 3A and 4A, the same members as those in FIG. 1A are denoted by the same reference numerals. The gap 43 is a portion where the distance between the low potential side electrode 6 and the first high potential side electrode 5 is shortest. Although not shown, a light emitting member is disposed outside the anode 20 (on the side opposite to the side where the electron-emitting device is located). The difference between FIG. 3A and FIG. 4A is that the third insulating layer 7 and the second high potential side electrode 8 are laminated on the low potential side electrode 6 in FIG. 4A. It is. Vf is a voltage applied between the low potential side electrode 6 and the first high potential side electrode 5 and between the low potential side electrode 6 and the second high potential side electrode 8, Va is a low potential side electrode 6 and the anode. 20 is a voltage to be applied.

  When the voltage Vf is applied to the electron-emitting devices shown in FIGS. 3A and 4A, electrons are emitted from the gap 43. Considering FIG. 3A, electrons emitted from the gap 43 are directed to the high potential side electrode 5 and the electrode 12 and repeatedly scattered several times on the surface of the high potential side electrode 5 or the electrode 12. When the voltages Vf and Va are simultaneously applied, a point where an equipotential line corresponding to the potential of the high potential side electrode 5 intersects the surface of the high potential side electrode 5 or the electrode 12 is generated. This is the stagnation point 35. Electrons that have repeatedly scattered several times on the surface of the high potential side electrode 5 or the electrode 12 are horizontal before appearing from the equipotential line passing through the stagnation point 35 to the outside (right side in FIG. 3A). It is accelerated in the direction (right side as viewed in FIG. 3A). Electrons that exceed the stagnation point are accelerated by the voltage Va and reach the anode 20, but during that time, almost no force is applied in the horizontal direction, so that the movement in the horizontal direction is substantially constant. Therefore, the anode arrival position of the electrons emitted from the gap 43 is shifted to the right side as viewed in FIG. That is, the direction in which the electron arrival position of the electrons is shifted is opposite to that in the conventional configuration as shown in FIG. This is because the arrangement of the high-potential-side electrode 5 and the low-potential-side electrode 6 is reversed when viewed from the gap where electrons are emitted, and the force due to the horizontal electric field received by the emitted electrons is also reversed. Because.

  However, in FIG. 3A, the anode 20 is disposed on the side opposite to the high potential side electrode 5 when viewed from the low potential side electrode 6. The electrons emitted from the gap 43 are first accelerated toward the lower side where the high-potential-side electrode 5 is present to obtain a downward velocity. Since the anode 20 is on the side opposite to the high potential side electrode 5, it is not easily affected by the voltage Va applied to the anode 5, and is only affected by the force pulled by the high potential side electrode 5, and further toward the lower side. Because of the acceleration, the number of times of scattering at the high potential side electrode 5 increases.

  Next, considering the configuration of FIG. 4A, the low potential side electrode 6 is sandwiched between the first high potential side electrode 5 and the second high potential side electrode 8 that is equipotential thereto. Therefore, an equipotential line that connects between the first high potential side electrode 5 and the second high potential side electrode 8 is generated. Among the electrons emitted from the gap 43, a velocity component in the right direction as viewed in FIG. 4A is obtained as in FIG. 3A, and the first high potential side electrode 5 and the second high potential side are obtained. There are a relatively large number of electrons that draw orbits away from any of the electrodes 8. Therefore, the anode arrival position of the electrons emitted from the gap 43 is shifted to the right side as seen in FIG. 4A as in FIG. At the same time, the number of times of scattering at the high potential side electrode can be reduced as compared with FIG.

  The electrons that have reached the anode 20 cause the light emitting member disposed outside the anode 20 to emit light and display an image. The light emission pattern of the light emitting member obtained by the electron emission element having the configuration shown in FIG. 3A is shown in FIG. 3B, and the light emission pattern of the light emission member obtained by the electron emission element having the configuration shown in FIG. Is shown in FIG. The contour line of the light emission pattern indicates a 10% range of the peak luminance. The size Lx, Ly (beam diameter) of the contour line of the light emission pattern is estimated by simulation. When the vertical distance H = 1.6 mm, Va = 11.8 kV, and Vf = 23 V from the surface of the substrate 1 to the anode 20 in FIGS. 3A and 4A, Lx = in FIG. 3A. 140 μm, Ly = 250 μm. In FIG. 4B, Lx = 130 μm and Ly = 250 μm. Further, when the electron emission efficiency η is estimated by simulation with the configuration shown in FIGS. 3A and 4A, it is 1.5% in FIG. 3A and 5.5% in FIG. 4A. Therefore, as shown in FIG. 4A, the electron emission efficiency is significantly improved by arranging the high potential side electrodes 5 and 8 on both sides of the gap 43 for emitting electrons.

<Both sides, one forward electrode, the other reverse electrode + second high potential side electrode>
FIG. 5A is a schematic diagram showing the configuration of a preferred embodiment of the image display device of the present invention, and the equipotential lines and the trajectory of the electron trajectory formed. The configuration of the electron-emitting device in FIG. 5A is configured as shown in FIG. 4A on one side surface (right side as viewed in FIG. 2A) as compared to the configuration in FIG. It can be said that the structure of the electron-emitting device is replaced with. In FIG. 5A, the same members as those in FIG. Although not shown, a light emitting member is disposed outside the anode 20 (on the side opposite to the side where the electron-emitting device is located).

  As for the electrons emitted from the gap 9 in FIG. 5A, the anode arrival position of the electrons is shifted to the right as viewed in FIG. On the other hand, the electrons emitted from the gap 10 in FIG. 5A are equivalent to the configuration in FIG. 4A, so that the anode arrival position of the electrons is shifted to the right as viewed in FIG. That is, the position where electrons reach the anode is shifted in the same direction (right side) as viewed in FIG. The electrons that have reached the anode 20 cause the light emitting member disposed outside the anode 20 to emit light and display an image.

  FIG. 5B shows a light emission pattern of the light emitting member obtained by the electron-emitting device having the configuration shown in FIG. The contour line of the light emission pattern indicates a 10% range of the peak luminance. The solid outline is mainly due to electrons emitted from the gap 10, and the dashed outline is mainly due to electrons emitted from the gap 9, and the anode arrival positions of the electrons emitted from the gaps 9 and 10 are almost the same. Is in position. When the sizes Lx and Ly (beam diameters) of the contour lines of the light emission pattern are estimated by simulation, the vertical distance H = 1.6 mm and Va = 11.8 kV from the surface of the substrate 1 to the anode 20 in FIG. , Vf = 23 V, Lx = 130 μm and Ly = 250 μm. Compared with the light emission pattern (see FIG. 2B) obtained with the configuration as shown in FIG. 2A, the beam diameter in the y direction is slightly widened, but the beam diameter in the x direction is greatly suppressed. I understand that. Further, when the electron emission efficiency η is estimated by simulation with the configuration shown in FIG. 5A, it is 5.5%, which is almost equivalent to the configuration shown in FIG.

  From the above, it can be seen that in the electron-emitting device having the configuration as shown in FIG. 5A, the current increases, a high electron-emitting efficiency can be obtained, and the characteristics in which the beam diameter at the anode 20 is suppressed can be obtained.

〔Production method〕
With reference to FIG. 6, an example of the manufacturing method of the electron-emitting device illustrated in FIG. FIG. 6 is a schematic view showing a manufacturing process of the electron-emitting device shown in FIG.

<Formation of substrate 1>
A substrate 1 in FIG. 6 is a substrate for mechanically supporting the element, and is a quartz glass, glass with reduced impurity content such as Na, blue plate glass, and a silicon substrate. The necessary functions of the substrate include not only high mechanical strength but also resistance to alkalis and acids such as dry etching, wet etching, and developer, and film formation when used as an integrated display panel. A material or a material having a small difference in thermal expansion from other laminated members is desirable. Further, it is desirable to use a material in which alkali elements or the like from the inside of the glass are difficult to diffuse with heat treatment.

<Formation of insulating layers 101 and 102>
First, as shown in FIG. 6A, insulating layers 101 and 102 are stacked on the substrate 1 in order to form a first insulating member. The insulating layers 101 and 102 are insulating films made of a material with excellent workability, such as SiN (Si _x N _y ) or SiO ₂ , and the manufacturing method thereof is a general vacuum film forming method such as a sputtering method. The CVD method and the vacuum deposition method are used. The thickness of the insulating layer 101 is set in the range of 20 nm to 50 μm, preferably in the range of 50 nm to 500 nm, and the insulating layer 102 is set in the range of 20 nm to 500 nm, preferably 20 nm to 50 nm. Selected by range. Note that in order to recede the side surface of the insulating layer 102 after the insulating layers 101 and 102 are stacked, the relationship between the insulating layer 101 and the insulating layer 102 is set so as to have different etching amounts with respect to etching. Desirably, the ratio of the etching amount between the insulating layer 101 and the insulating layer 102 is desirably 10 or more, and desirably 50 or more. For example, the insulating layer 101 can be made of Si _x N _y , and the insulating layer 102 can be made of an insulating material such as SiO ₂ , PSG having a high phosphorus concentration, a BSG film having a high boron concentration, or the like.

<Formation of conductive layer 103>
Further, a conductive layer 103 is stacked as shown in FIG. The conductive layer 103 is formed by a general vacuum film forming technique such as vapor deposition or sputtering. The material of the conductive layer 103 is preferably a material having high thermal conductivity and high melting point in addition to conductivity. For example, metals or alloy materials such as Be, Mg, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Al, Cu, Ni, Cr, Au, Pt, and Pd can be used. Also, carbides such as TiC, ZrC, HfC, TaC, SiC, WC, borides such as HfB ₂ , ZrB ₂ , CeB ₆ , YB ₄ , GdB ₄ , nitrides such as TiN, ZrN, HfN, TaN, Si, A semiconductor such as Ge can also be used. Moreover, organic polymer materials, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, a carbon compound, and the like can be used as appropriate. Further, the thickness of the conductive layer 103 is set in the range of 20 nm to 500 nm, and preferably selected in the range of 50 nm to 500 nm.

<Processing the conductive layer 103>
After a resist pattern is formed on the conductive layer 103 by a photolithography technique, the conductive layer 103 is processed using an etching method, and the third side surface 23 is formed as shown in FIG. 6B. In such an etching process, RIE (Reactive Ion Etching) is generally used in which an etching gas is turned into plasma and irradiated on the material to enable precise etching of the material. As the processing gas at this time, a fluorine-based gas such as CF ₄ , CHF ₃ , or SF ₆ is selected in the case of producing a fluoride as a target member to be processed. In the case of forming a chloride such as Si or Al, a chlorine-based gas such as Cl ₂ or BCl ₃ is selected. Further, hydrogen, oxygen, argon gas, or the like is added as needed to obtain a selection ratio with the resist, to ensure the smoothness of the etched surface, or to increase the etching speed.

<Formation of insulating layer 105>
Subsequently, an insulating layer 105 is stacked as shown in FIG. The insulating layer 105 is an insulating film made of a material with excellent workability, and is, for example, SiN (Si _x N _y ) or SiO ₂ , and its manufacturing method is a general vacuum film forming method such as a sputtering method, CVD, or the like. Formed by a vacuum evaporation method. The thickness of the insulating layer 105 is set in the range of 20 nm to 50 μm, and preferably in the range of 50 nm to 500 nm. However, the thickness of the insulating layer 105 needs to be larger than the thickness of the insulating layer 102 so that electrons are not emitted between the second high potential side electrode 8 and the second low potential side electrode 6. Note that, since the sixth side surface 26 is retracted after the insulating layer 105 is stacked, the insulating layer 101 and the insulating layer 105 are set so as to have different etching amounts with respect to etching. Desirably, the ratio of the etching amount between the insulating layer 101 and the insulating layer 105 is desirably 10 or more, and desirably 50 or more. For example, the insulating layer 101 can be made of Si _x N _y , and the insulating layer 105 can be made of an insulating material such as SiO ₂ , PSG having a high phosphorus concentration, a BSG film having a high boron concentration, or the like.

<Processing the insulating layer 105>
A resist pattern is formed on the insulating layer 105 by a photolithography technique and then processed using an etching technique to form the fifth side face 25 as shown in FIG. As such etching processing, the method described in the processing of the conductive layer 103 can be used.

<Formation of conductive layer 107>
Subsequently, a conductive layer 107 is laminated as shown in FIG. The conductive layer 107 is formed by a general vacuum film forming technique such as vapor deposition or sputtering. The conductive layer 107 may be any material that is conductive and emits electric field, and is generally a high melting point of 2000 ° C. or higher and a work function material of 5 eV or lower, and it is difficult to form a chemical reaction layer such as an oxide or A material capable of easily removing the reaction layer is preferable. As such a material, for example, a metal or alloy material such as Hf, V, Nb, Ta, Mo, W, Au, Pt, and Pd can be used. Further, the carbides, borides, and nitrides mentioned as the material for forming the conductive layer 103 can also be used. Furthermore, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, a carbon compound, and the like can also be used. The conductive layer 107 is formed by a general vacuum film forming technique such as vapor deposition or sputtering. Further, the thickness of the conductive layer 107 is set in the range of 20 nm to 500 nm, and is preferably selected in the range of 50 nm to 500 nm.

<Etching each layer>
After a resist pattern is formed over the conductive layer 107 by a photolithography technique, the conductive layer 107, the insulating layer 105, the conductive layer 103, the insulating layer 102, and the insulating layer 101 are sequentially processed by an etching method. As a result, as shown in FIG. 6F, the first insulating layer 2, the insulating layer 102, the second low potential side electrode 6, the insulating layer 105, and the second high potential side electrode 8 are obtained. In addition, by this process, the first side surface 21 and the second side surface 22 of the first insulating layer 2, the seventh side surface 27 of the high potential side electrode 8 that coincides with the extended surface of the first side surface 21, A fourth side surface 24 of the second low potential side electrode 6 is formed on the extended surface of the second side surface 22. Further, although the eighth side surface 28 of the second high potential side electrode 8 is also formed on the extended surface of the second side surface 22, the electric field described with reference to FIG. As long as it is configured, it is not limited to such a configuration. As the etching method, the method described in the processing of the conductive layer 103 can be used.

<The second insulating layer 3 and the third insulating layer 7 are formed by retreating the side surfaces of the insulating layers 102 and 105>
As shown in FIG. 6G, the insulating layer 102 and the insulating layer 105 are etched to retract the exposed side surfaces inward. As a result, the second insulating layer 3 having side surfaces that recede inward from the first side surface 21 and the second side surface 22 is formed. That is, the first recess 13 and the second recess 14 of the first insulating member are formed. At the same time, the third insulating layer 7 having the sixth side face 26 that recedes inward from the second side face 22 and the fourth side face 24 is formed. For example, if the insulating layers 102 and 105 are made of SiO ₂ , the etching may be a material made of Si _x N _y using a mixed solution of ammonium fluoride and hydrofluoric acid, commonly called buffer hydrofluoric acid (BHF). For example, a hot phosphoric acid etching solution can be used. The distance L (depth of the first recess 13) from the side surface 21 of the first insulating layer 2 to the side surface of the second insulating layer 3 is deeply related to the leakage current after the element is formed, and the larger L is formed. The value of the leakage current is reduced. However, if the distance is formed too deep, problems such as deformation of the high potential side electrode occur. For this reason, L is formed with a thickness of about 30 nm to 200 nm. Similarly, the depth L of the second recess 14 is also formed to be about 30 nm to 200 nm.

<Formation of release layer 109>
As shown in FIG. 6 (h), a release layer 109 is formed on the surfaces of the second high potential side electrode 8 and the second low potential side electrode 6. The purpose of forming the peeling layer 109 is to peel the conductive film 110 deposited in the next step from the second high potential side electrode 8 and the second low potential side electrode 6. For this purpose, the release layer 109 is formed by a method such as attaching a release metal by electrolytic plating, for example.

<Formation of Conductive Film 110>
As shown in FIG. 6 (i), the conductive film 110 is formed on the outer surface of the second high potential side electrode 8, the fourth side surface 24 of the second low potential side electrode 6, and the first surface of the first insulating layer 2. The first and second side surfaces 21 and 22 are attached. For the conductive film 110, the same material as that of the conductive layer 107 is preferably used, and the formation method is also the same. Next, as shown in FIG. 6J, the peeling layer 110 is removed by etching, so that the conductive film 110 on the outer surfaces of the second high potential side electrode 8 and the second low potential side electrode 6 is removed. Thus, the first low potential side electrode 4 and the first high potential side electrode 5 are formed. A preferable thickness of the conductive film 110 is 5 nm to 80 nm. Next, as shown in FIG. 6 (k), an electrode 11 is formed to establish electrical continuity with the first low potential side electrode 4, and electrical continuity is established with the first high potential side electrode 5. Therefore, the electrode 12 is formed. The electrodes 11 and 12 have conductivity similar to the conductive film 110, and are formed by a general vacuum film forming technique such as vapor deposition or sputtering, or a photolithography technique. As the material of the electrodes 11 and 12, the same material as that of the conductive layer 103 is preferably used. The thickness of the electrodes 11 and 12 is set in the range of 50 nm to 5 mm, and preferably selected in the range of 50 nm to 5 μm.

  Next, the electron source substrate and the image display device of the present invention will be described with reference to FIG. FIG. 9A is a schematic plan view showing a preferred embodiment of the electron source substrate of the present invention. FIG. 9B is a schematic diagram showing a cross-sectional structure of an example of the image display device of the present invention.

  As shown in FIG. 9A, the electron source substrate 93 of the present invention includes a plurality of electron-emitting devices 92 of the present invention on the substrate 1. The element 92 is connected to a matrix wiring composed of a signal line 90 and a scanning line 91, and electron emission from a predetermined address is controlled by a drive circuit (not shown).

  As shown in FIG. 9B, the image display device 96 of this example is a vacuum container in which an electron source substrate 93 having an electron-emitting device 92 and a light-emitting substrate 97 are combined so as to face each other, and a frame 94 is arranged around them. It is produced by forming. The light emitting substrate 97 includes at least an anode and a light emitting member stacked on the anode. In general, a phosphor or the like is disposed as a light emitting member inside a transparent substrate such as a glass substrate, and an anode is disposed further inside. In addition, in the image display device 96 formed as a vacuum container, a spacer (not shown) is usually interposed between the light emitting substrate 97 and the electron source substrate 93 in order to maintain atmospheric pressure resistance. A high voltage is supplied to the anode of the light emitting substrate 97 from a high voltage power source (not shown), and the light emitted from the electron source substrate 93 is irradiated to the light emitting member of the light emitting substrate 97 to emit light.

  The preferred embodiments of the present invention have been described above. However, the present invention can be implemented in various modes different from the above embodiments without departing from the gist of the present invention.

Example 1
The electron-emitting device having the configuration shown in FIG. 1 was fabricated according to the process of FIG. First, as shown in FIG. 6A, a low-sodium glass PD 200 is used as the substrate 1, and a SiN (Si _x N _y ) film having a thickness of 500 nm is formed as the insulating layer 101 by sputtering, followed by insulation. A SiO ₂ film having a thickness of 23 nm was formed as the layer 102 by sputtering. Further, a TaN film having a thickness of 30 nm was formed as a conductive layer 103 on the insulating layer 102 by a sputtering method. Next, after forming a resist pattern on the conductive layer 103 by a photolithography technique, the conductive layer 103 was processed using a dry etching method, and the third side surface 23 was formed as shown in FIG. 6B. . As the processing gas at this time, a CF ₄ -based gas was used for the conductive layer 103 because a material for forming a fluoride was selected as described above. After removing the resist, as shown in FIG. 6C, a SiO ₂ film having a thickness of 40 nm was formed as the insulating layer 105 by sputtering.

Next, after forming a resist pattern on the insulating layer 105 by a photolithography technique, the insulating layer 105 was processed using a dry etching method, and the fifth side surface 25 was formed as shown in FIG. . As the processing gas at this time, CF ₄ -based gas was used for the insulating layer 105 because the material for producing fluoride was selected as described above. After the resist was peeled off, a molybdenum (Mo) film having a thickness of 30 nm was formed as the conductive layer 107 by sputtering as shown in FIG. Next, after a resist pattern was formed on the conductive layer 107 by a photolithography technique, the conductive layer 107, the insulating layer 105, the conductive layer 103, the insulating layer 102, and the insulating layer 101 were sequentially processed by a dry etching method. As a result, as shown in FIG. 6 (f), a laminate composed of the first insulating layer 2, the insulating layer 102, the second low potential side electrode 6, the insulating layer 105, and the second high potential side electrode 8 is formed. Formed. The resist pattern was formed so that the width of the high potential side electrode 8 (distance between the first side surface 21 and the second side surface 22) was 10 μm after dry etching. As a processing gas at this time, CF ₄ type gas is used for the conductive layer 107, the insulating layer 105, the conductive layer 103, the insulating layer 102, and the insulating layer 101 because the material for forming fluoride is selected as described above. Using.

  After the resist is removed, as shown in FIG. 6G, the insulating layer 102 and the insulating layer 105 are etched using BHF so that the depth of the recess becomes about 120 nm, and the second insulating layer 3 and the second insulating layer 105 are etched. 3 insulating layers 7 were formed. Next, as shown in FIG. 6H, Ni was electrolytically deposited on the surfaces of the second high potential side electrode 8 and the second low potential side electrode 6 by electrolytic plating to form a release layer 109. As shown in FIG. 6 (i), molybdenum (Mo) was formed as the conductive film 110 by EB vapor deposition. First, the film is formed by setting the angle of the substrate to 60 ° clockwise as viewed in FIG. 6 (i) with respect to the horizontal plane, and then the counterclockwise angle of the substrate with respect to the horizontal plane as viewed in FIG. 6 (i). The film was set at 60 °. The deposition rate was determined so that the deposition was about 12 nm / min. Then, the deposition time is precisely controlled (in this example, 1 minute for a clockwise 60 ° set, 1 minute for a 60 ° counterclockwise set), and the first side surface 21 and the second side surface 22 of the first insulating layer 2 are applied. Each 18 nm thick Mo was formed. After forming the Mo film, as shown in FIG. 6 (j), the Ni peeling layer 109 is removed using an etching solution made of iodine and potassium iodide, whereby the second high potential side electrode 8, the second The Mo material 110 was peeled from the low potential side electrode 6.

  After the electron-emitting device was formed by the above method, the electron emission characteristics were evaluated with the configuration shown in FIG. A light emitting member was disposed outside the anode 20 (on the side opposite to the side where the electron-emitting device is located). As a result, when Vf = 23 V and Va = 11.8 kV were applied, If = 61 μA, Ie = 3.2 μA, and η = 5.2%. The light emission pattern obtained by the electron beam apparatus of this example is as shown in FIG. 5B. When the peak luminance ranges Lx and Ly were measured, Lx = 135 μm and Ly = 255 μm.

(Comparative Example 1)
Next, an electron-emitting device having a configuration as shown in FIG. 2A was fabricated according to the process shown in FIG. First, the insulating layer 101, the insulating layer 102, and the conductive layer 103 were formed as in Example 1 (FIG. 7A). Then, after forming a resist pattern on the conductive layer 103 by a photolithography technique, the conductive layer 103, the insulating layer 102, and the insulating layer 101 are sequentially processed using a dry etching method, and the insulating layer 2, the insulating layer 102, and the high potential side are processed. An electrode 31 was formed (FIG. 7B). After removing the resist, the insulating layer 102 was etched in the same manner as in Example 1 to form the insulating layer 3 (FIG. 7C). Thereafter, as in Example 1, a release layer 109 is formed on the surface of the high potential side electrode 31 (FIG. 7D), and the side surface of the insulating layer 2, the surface of the high potential side electrode 31, and the surface of the substrate 1 are electrically conductive. The property film | membrane 110 was formed (FIG.7 (e)). Thereafter, the release layer 109 was removed, and the conductive film 110 on the high potential side electrode 31 was peeled off (FIG. 7F).

  After forming the electron-emitting device by the above method, the anode and the light emitting member were arranged in the same manner as in Example 1, and the characteristics of the electron-emitting device were evaluated in the same manner as in Example 1. As a result, when Vf = 23 V and Va = 11.8 kV were applied, If = 60 μA, Ie = 3.2 μA, and η = 5.3%. The light emission pattern obtained by the electron beam apparatus of this example is as shown in FIG. 2A. When the peak luminance ranges Lx and Ly were measured, Lx = 240 μm and Ly = 235 μm. Compared to Example 1, in this example, the currents Ie, If and electron emission efficiency η are substantially the same, and the beam diameter at the anode is slightly wider in the Y direction (Ly) in Example 1, but in the X direction. (Lx) was significantly narrowed, and the effect of the present invention could be confirmed.

(Example 2)
In this example, as shown in FIG. 8A, an electron source substrate in which a plurality of the electron-emitting devices of Example 1 are arranged on the substrate is configured. The basic manufacturing method is the same as that of Example 1 (FIGS. 6A to 6K). Four electron-emitting devices are arranged side by side, the width (W1) of the high potential side electrode 8 is 10 μm, and the distance (W2) from the end of the high potential side electrode 8 to the end of the adjacent high potential side electrode 8 A resist pattern was formed so as to be 10 μm.

  After the electron source was formed by the above method, the anode and the light emitting member were arranged in the same manner as in Example 1, and the electron emission characteristics were evaluated in the same manner as in Example 1. As a result, Vf = 23V and Va = 11.8kV. Were applied, If = 232 μA, Ie = 12.5 μA, and η = 5.4%. The light emission pattern obtained by the electron beam apparatus of this example is shown in FIG. The contour line of the light emission pattern indicates a 10% range of the peak luminance. Looking at the light emission pattern of FIG. 8B, the light emission pattern obtained in Example 1 (FIG. 2B) is almost equal to the shape of the horizontal superimposition, and the influence of the electric field formed by the adjacent laminates. Was not big. When the peak luminance ranges Lx and Ly in FIG. 8B were measured, Lx = 200 μm and Ly = 255 μm.

  4: 1st low potential side electrode, 5: 1st high potential side electrode, 6: 2nd low potential side electrode, 8: 2nd high potential side electrode, 20: Anode, 21: 1st side surface , 22: second side, 23: fourth side, 24: fourth side, 25: fifth side, 26: sixth side, 27: seventh side

Claims (3)

An upper surface and first and second side surfaces sandwiching the upper surface; a first recess on the upper surface side end portion of the first side surface; and a second recess surface on the upper surface side end portion of the second side surface. A first insulating member having a recess;
A first low potential side electrode disposed on the first side and having one end along the edge of the first recess;
A first high-potential side electrode disposed on the second side surface and having one end along the edge of the second recess;
A first side surface having a third side surface at a position retracted inward from the first concave portion, and a fourth side surface that coincides with an extended surface of the second side surface; A second low-potential side electrode disposed on the upper surface of the member and facing the first high-potential side electrode via the second recess;
A fifth side surface at a position retracted inward from the first recess, a sixth side surface at a position retracted inward from the fourth side surface, and a second side of the second low potential side electrode. A second insulating member disposed on the second low-potential side electrode so as to cover the side surface of the second low-potential side electrode;
The first insulating member has a seventh side surface that coincides with the extended surface of the first side surface, and faces the first low potential side electrode through the first recess. And a second high potential side electrode disposed on the second insulating member;
An electron-emitting device comprising:   2. An electron source substrate comprising a substrate, a plurality of electron-emitting devices disposed on the substrate, and a wiring for applying a voltage to the electron-emitting devices, wherein the electron-emitting devices are defined in claim 1. An electron source substrate characterized by being an electron-emitting device. An electron source substrate according to claim 2,
An anode disposed opposite to the first low potential side electrode and the first high potential side electrode with a second high potential side electrode of the electron-emitting device formed on the electron source substrate interposed therebetween; A light emitting member that is disposed in a stacked manner and emits light by irradiation of electrons emitted from the electron emitter,
An image display device comprising:

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