JP2010186615A - Electron beam device and image display using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron beam device equipped with an electron-emitting element having a simple configuration and high electron emission efficiency, operating stably, and with emitted electron beams effectively converged. <P>SOLUTION: On a substrate 1, an insulation member 3 and a gate 5 are formed, a concave part 7 is formed on the insulation member 3, a cathode 6 is arranged on a side surface of the insulation member 3. A gate 5 is formed in a concavo-convex shape having a retreat part9 protruding a region corresponding to the cathode 6 and retreating gate end parts on both sides of the region, the surface of the insulation member 3 exposed to the retreat part 9 is made retreat at least to a surface of an insulation layer 3a to form a control electrode 13 on the surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electron beam apparatus including an electron-emitting device that emits electrons, which is used for a flat panel display.

  Conventionally, there are electron-emitting devices in which a large number of electrons emitted from a cathode collide with an opposing gate and are scattered and then taken out as electrons. As a device that emits electrons in such a form, a surface conduction electron-emitting device and a stacked electron-emitting device are known. Patent Document 1 discloses a high-efficiency electron emission in which the gap of the electron-emitting portion is 5 nm or less. Elements have been proposed. Patent Document 2 discloses a stacked electron-emitting device, and conditions for enabling high-efficiency electron emission are given as a function of gate material thickness, drive voltage, and insulating layer thickness. . Further, Patent Document 3 discloses a configuration in which a stacked electron-emitting device is provided with a recess (recess portion) in an insulating layer near the electron-emitting portion.

JP 2000-251643 A JP 2001-229809 A JP 2001-167893 A

  In the element disclosed in Patent Document 1, there are a plurality of electron emission points in the formed gap, whereby discharge and the like in the electron emission part are suppressed, and an electron emission element that is stable for a long time can be provided. It is said. However, even though the discharge at the electron emission portion can be suppressed, the problem that the amount of electron emission from each point of the electron emission point increases or decreases with the drive time for driving the element has not been sufficiently solved. In addition, a phenomenon has occurred in which the number of electron emission points in the gap increases or decreases with the driving time of the electron-emitting device.

  Also in the element of Patent Document 2, a phenomenon similar to the above has been found, and a more stable electron-emitting element has been desired.

  Furthermore, in the element of Patent Document 3, the electron emission efficiency is good, but further improvement in characteristics has been demanded.

  An object of the present invention is to provide an electron beam apparatus including an electron-emitting device that has a simple configuration, high electron emission efficiency, operates stably, and focuses an emitted electron beam well, and an image using the electron beam apparatus It is to provide a display device.

The first of the present invention is an insulating member having a recess on the surface;
A gate located on the surface of the insulating member;
At least one cathode located on the surface of the insulating member so as to project from the edge of the recess toward the gate, the projecting portion facing the gate;
An anode disposed opposite to the protruding portion with the gate interposed therebetween;
The gate is formed on the surface of the insulating member so that a region facing the cathode protrudes, and a gate end portion of a region sandwiching the protruding region has a retreated portion,
Retreat until the surface of the insulating member facing the anode through the receding portion reaches at least the edge on the cathode side of the recess, and a control electrode is disposed in a region facing the anode through the receding portion,
The voltage applied between the cathode and the gate is Vf [V], the voltage applied between the control electrode and the cathode is Vc [V], and the voltage applied between the anode and the cathode is Va [V]. ] When the distance from the surface opposite to the side where the gate of the insulating member is disposed to the anode is h [m], and the width of the protruding region of the gate is T5 [m],
T5 <5 × (Vf / Va) × (h / π)
Vf ≧ Vc
This is an electron beam apparatus.

  The first electron beam apparatus of the present invention includes a configuration in which two or more of the cathodes are provided and the gate is formed in a comb shape on the surface of the insulating member.

The second of the present invention is an insulating member having a recess on the surface;
A gate located on the surface of the insulating member;
A cathode portion protruding from the edge of the recess toward the gate, the cathode positioned on the surface of the insulating member such that the protrusion portion faces the gate;
An anode disposed opposite to the protruding portion with the gate interposed therebetween;
The surface of the insulating member on the side where the gate is disposed has a receding portion that recedes at least around the cathode side edge of the concave portion around the gate;
A control electrode is disposed on the surface of the receding portion;
The voltage applied between the cathode and the gate is Vf [V], the voltage applied between the control electrode and the cathode is Vc [V], and the voltage applied between the anode and the cathode is Va [V]. ] The distance from the surface of the insulating member opposite to the side where the gate is disposed to the anode is h [m], the width of the region facing the cathode of the gate is T5 [m], and the gate surface facing the anode When the length of the gate in the direction orthogonal to the edge on the side facing the cathode is T5x [m],
T5 <5 × (Vf / Va) × (h / π)
T5x <5 × (Vf / Va) × (h / π)
Vf ≧ Vc
This is an electron beam apparatus.

  The second electron beam apparatus according to the present invention preferably includes a configuration having two or more sets of the cathode and the gate facing the cathode.

  A third aspect of the present invention is an image display device comprising the first or second electron beam apparatus according to the present invention and a light emitting member located outside the anode.

  According to the present invention, since the electric field is controlled by providing the control electrode around the gate, the emitted electron beam can be focused well. Therefore, it is possible to provide an image display device capable of displaying a high-quality image using the electron-emitting device.

It is a perspective view which shows typically the structure of one Embodiment of the electron-emitting element of the 1st electron beam apparatus of this invention. It is a plane schematic diagram of the electron-emitting device of FIG. 1A. It is a cross-sectional schematic diagram of the electron-emitting device of FIG. 1B. It is a cross-sectional schematic diagram of the electron-emitting device of FIG. 1B. It is a perspective view which shows typically the structure of another embodiment of the electron-emitting element of the electron beam apparatus of this invention. It is a cross-sectional schematic diagram of the electron-emitting device of FIG. 2A. It is an electron orbit figure in the structure which does not provide a retreat part in a gate and does not have a control electrode. FIG. 1C is an electron trajectory diagram in the C-C ′ cross section of FIG. 1B. It is a figure which shows the relationship between receding distance T8 of the receding part in this invention, and the size of an electron beam. It is a figure which shows the relationship between width T5 of the protrusion area | region of a gate, and the size of an electron beam. It is a figure which shows the manufacturing process of the electron emission element which concerns on this invention. It is a figure which shows the manufacturing process of the electron emission element which concerns on this invention. It is a schematic diagram which shows the structure which measures the electron emission characteristic of the electron beam apparatus of this invention. It is a perspective view which shows typically the structure of the element of the comparative example produced in the Example of this invention. FIG. 3B is a partially enlarged view of the vicinity of the end of the gate of FIG. 3B. It is a perspective view which shows typically the structure of one Embodiment of the electron-emitting element of the 2nd electron beam apparatus of this invention. FIG. 10B is a plan view of the electron-emitting device in FIG. 10A. It is a cross-sectional schematic diagram of the electron-emitting device of FIG. 10B. It is a cross-sectional schematic diagram of the electron-emitting device of FIG. 10B. It is a top view which shows typically the structure of an example of the electron source of the image display apparatus 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 top view which shows typically the structure of the fluorescent film used for the image display apparatus of this invention. It is a schematic diagram which shows the structural example of the drive circuit for performing the television display based on the television signal of an NTSC system on the display panel comprised using the electron source shown to FIG. 11A. It is a figure which shows the relationship between Va and Vf in the electronic device of this invention, and the size of an electron beam. It is the figure which normalized the relationship shown by FIG. 12A with T5 = 100 micrometer.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the following embodiments are not intended to limit the scope of the present invention only to those unless otherwise specified.

[Configuration overview]
The electron beam apparatus of the present invention includes an electron-emitting device that emits electrons, and an anode that the electrons emitted from the electron-emitting devices reach.

  1A to 1D are schematic views showing a configuration of an electron-emitting device according to a preferred embodiment of the first electron beam apparatus of the present invention. FIG. 1A is a perspective view, FIG. 1B is a plan view, and FIG. 1C is in FIG. AA ′ sectional view, FIG. 1D is a BB ′ sectional view in FIG. 1B.

  1A to 1D, 1 is a substrate, 2 is an electrode, 3 is an insulating member, and is formed of a laminate of insulating layers 3a and 3b. Reference numeral 5 denotes a gate, and reference numeral 6 denotes a cathode, which is electrically connected to the electrode 2. 5 a is a side surface of the gate 5, and 5 b is a bottom surface of the gate 5 exposed in the recess 7. Reference numeral 7 denotes a concave portion of the insulating member 3, and in this example, only the side surface of the insulating layer 3 b is recessed inward from the side surface of the insulating layer 3 a. 8 is a gap (shortest distance from the tip of the cathode 6 to the bottom surface 5b of the gate 5) in which an electric field necessary for electron emission is formed.

  In the electron-emitting device according to the present invention, as shown in FIGS. 1A to 1D, the gate 5 is formed on the surface of the insulating member 3 (upper surface in this example). On the other hand, the cathode 6 is also formed on the surface (side surface in this example) of the insulating member 3 and has a protruding portion protruding from the edge of the recessed portion 7 toward the gate 5 on the side facing the gate 5 with the recessed portion 7 interposed therebetween. Yes. Therefore, the cathode 6 faces the gate 5 through the gap 8 at the protruding portion. In the present invention, the cathode 6 is defined at a lower potential than the gate 5. Although not shown in FIGS. 1 to 1D, an anode defined at a higher potential than these is provided at a position facing the cathode 6 via (intervening) the gate 5. In the image display device using the electron beam apparatus of the present invention, the light emitting member is disposed outside the anode (on the side opposite to the side where the electron-emitting device is located).

  In the present invention, at least one cathode 6 is formed in one element, and preferably has two or more as described later. This example is an example having two.

  The insulating member is formed so that the gate 5 has a concavo-convex end that protrudes from a region facing the cathode 6 and has a recess 9 in which the gate ends of the regions on both sides sandwiching the protruding region 12 (protruding region) are retreated. It is formed on the surface. That is, the tip of the projecting region 12 that hits the convex / concave shape is opposite to the cathode 6, and the region that hits the concave is the receding portion 9. When there are a plurality of cathodes 6, as shown in FIG. 1B, the gate 5 has a comb shape in a planar shape.

  Furthermore, in the present invention, the surface of the insulating member 3 exposed to the retreating portion 9, that is, the surface of the insulating member 3 facing the anode 11 described later, retreats at least until it reaches the cathode side edge of the recess 7. That is, when the insulating member 3 is a laminated body of the insulating layers 3a and 3b, the insulating layer 3b is removed in the receding portion 9 until the insulating layer 3a is exposed. In this example, the surface of the insulating member 3 is further retracted while leaving a part of the insulating layer 3a, and as shown in FIG. 2A, all of the insulating member 3 exposed to the retracted portion 9 may be removed. Absent. 2A is a perspective view of the embodiment of the present invention, and the plan view is the same as FIG. 1B. 2B is a cross-sectional view of FIG. 2A and corresponds to the B-B ′ cross section of FIG. 1B.

  In the present invention, the control electrode 13 is disposed in a region exposed in the receding portion 9 (in this example, a surface from which a part of the insulating layer 3a has been removed). The control electrode 13 is formed in an electrically insulated state from the cathode 6 and may control the potential independently. However, as shown in FIGS. 1A and 2A, the control electrode 13 is formed continuously with the cathode 6. This is preferable because the manufacturing process is simplified.

In the present invention, the length of each member of the electron-emitting device is defined as follows.
T1: Height of the gate 5 in the stacking direction (Z direction) of the gate 5 and the insulating member 3 T2: Height of the recess 7 of the insulating member 3 in the stacking direction (Z direction) of the gate 5 and the insulating member 3 (insulating layer 3b Height)
T3: distance from the edge on the cathode 6 side of the recess 7 of the insulating member 3 to the substrate 1 in the stacking direction (Z direction) of the gate 5 and the insulating member 3 (height of the insulating layer 3a)
T5: width of the protruding region 12 of the gate 5 (length of the protruding region 12 in the direction (Y direction) parallel to the opposite ends of the gate 5 and the cathode 6)
T6: Depth of the recess 7 (distance between the side surface of the insulating layer 3b and the side surface of the insulating layer 3a and the gate 5 in the recess 7 (length in the X direction))
T7: width of the receding portion 9 of the gate 5 (distance between the projecting regions 12) and a distance between the cathodes 6 when there are a plurality of cathodes 6 T8: receding distance of the receding portion 9 And the distance between the receding portion 9 and the side surface (the side surface at the most receded position) or the length of the protruding region 12 of the gate 5 in the X direction)
T9: Distance from the edge of the concave portion 7 of the insulating member 3 on the cathode 6 side to the surface of the control electrode 13 T13: Shortest distance between the tip of the cathode and the gate h: Surface opposite to the side where the gate of the insulating member 3 is disposed Distance from substrate to anode (distance from substrate 1 to anode)

[Effect of Providing Control Electrode 13 in Retreat Part 9]
FIG. 3B shows an electron trajectory in the CC ′ section of FIG. 1B. FIG. 3A is an electron trajectory diagram in a configuration in which the gate 5 is not provided with the recess 9 and the control electrode 13 is not provided. 3A and 3B, a solid line extending in the left and right direction is an equipotential line, and a broken line in the vertical direction on the paper surface indicates an electron trajectory. Reference numeral 11 denotes an anode.

  As shown in FIG. 3A, in the configuration without the retreating portion 9 and the control electrode 13, the potential hardly changes along the Y direction. Therefore, when the electron trajectory is observed from the X direction perpendicular to the YZ plane, the electrons are affected only by the anode 11 and the parallel electric field, and draw a trajectory spreading in a parabolic shape as shown in FIG. 3A.

  On the other hand, as shown in FIG. 3B, when the retracted portion 9 is provided in the gate 5 and the control electrode 13 is provided in the retracted portion 9, the potential along the Y direction is controlled by the control electrode 13 and the gate 5. Take a trajectory as shown by the broken line. That is, the spread of the electron beam in the Y direction is suppressed, and a focusing effect appears.

  Although it is expected that the retraction distance T8 of the retreating portion 9 is larger, the focusing effect is expected to be larger, but from the viewpoint of shortening tact, it is advantageous that T8 is smaller.

  FIG. 4 shows the relationship between T8 of the retreating portion 9 and the size of the electron beam in the Y direction. FIG. 4 shows a case where electrons are emitted from one region sandwiched between the retreat portions 9.

  In FIG. 4, the abscissa indicates the receding distance T8 of the receding portion 9 of the gate 5, and the ordinate indicates the electron beam size in the Y direction when reaching the anode 11. As can be seen from FIG. 4, the electron beam size in the Y direction decreases as the receding distance T8 of the receding portion 9 of the gate 5 increases, but tends to saturate above a certain value. This is because if the retracting portion 9 of a certain size is provided, the number of electrons flying to that extent decreases, so even if the retracting portion 9 is further increased, it does not contribute much to the reduction of the electron beam size in the Y direction. It is shown that.

[T5]
In the configuration of FIG. 1A, when the width T5 of the protruding region 12 of the gate 5 is reduced, the influence of the electric field generated by the potential difference between the control electrode 13 and the gate 5 becomes stronger, and the electron beam focusing effect is expected to be improved. it can.

This effect will be described with reference to FIGS. 3B and 9. FIG. 9 is an enlarged schematic view of the vicinity of the left side edge of the gate 5 of FIG. 3B. According to the present invention, the equipotential as shown in FIGS. 3B and 9 is obtained by the relationship between (1) the potential difference Vc between the gate 5 and the control electrode 13 and (2) the potential difference Va between the anode 11 and the cathode 6. The curve is distorted, and an equipotential line of V = Vc enters the gate 5 by a distance xs. This xs is a position where the electric field in the Z direction becomes zero, and is a position where the electric field of (1) and the electric field of (2) are balanced. The degree of overhang of Vc at this potential varies depending on Vc, Va, h, etc.
xs = (Vc / Va) × (h / π)
It is represented by Here, π is the circumference ratio. If T5 is small relative to this xs, it can be expected that the effect of focusing the electron beam will be enhanced.

  As T5 was made smaller, a decrease in the size of the electron beam in the Y direction was confirmed as T5 became smaller than a certain value. This is shown in FIG. The horizontal axis is T5 / xs. It was found that a focusing effect on the size of the electron beam in the Y direction appears at T5 / xs <5.

That is, in the present invention,
T5 <5 × (Vf / Va) × (h / π)
Vf ≧ Vc
It is necessary to satisfy.

  When T5 = 100 μm, the Y-direction beam size was about 300 μm, but it was found that the Y-direction beam size gradually decreased as T5 was decreased to 9 μm, 5 μm, 3 μm,.

[Va, Vf]
The configuration of FIG. 7 shows a power supply arrangement when measuring the electron emission characteristics of the device according to the present invention. As shown in FIG. 7, in the electron beam apparatus of the present invention, the anode 11 is disposed opposite the protruding portion of the cathode 6 with the gate 5 interposed. In this example, since the insulating member 3 is disposed on the substrate 1, it can be said that the anode 11 is disposed on the side of the substrate 1 where the insulating member 3 is disposed so as to face the substrate 1. .

  In FIG. 7, Vf is a voltage applied between the gate 5 and the cathode 6 of the device, If is a device current flowing at this time, Va is a voltage applied between the cathode 6 and the anode 11, and Ie is an electron emission current. is there.

  In FIG. 7, when the applied voltages Va and Vf are different, the electron beam size in the Y direction changes. 12A and 12B are graphs showing the relationship between Va, Vf and the electron beam size in the Y direction.

FIG. 12A shows the Y-direction beam size of three types of combinations of Va and Vf. However, as shown in FIG. 12B, by standardizing the electron beam size in the Y direction with the size when T5 is 100 μm, it is combined into one line. Xs in the graph is
xs = (Vc / Va) × (h / π)
It is represented by

  Here, π is the circumference ratio.

[Second Embodiment]
Next, the electron-emitting device of the second electron beam apparatus of the present invention will be described with reference to FIGS. 10A to 10D.

  The electron-emitting device according to the present invention is the electron-emitting device of the first electron beam apparatus described above, further expanding the receding portion 9 and the control electrode 13 formed in the region exposed to the receding portion 9, The gate 9 is surrounded by the portion 9 and the control electrode 13. That is, in the present invention, the gate 5 is formed in a rectangular shape as shown in FIG. 10A, and the control electrode 13 is disposed around the gate 5.

  In the present invention, the cathode 6 and the gate 5 opposed to the cathode 6 may be one set, but preferably have two or more sets spaced apart from each other. FIG. 10A shows an example of two sets.

  The configuration shown in FIGS. 10A to 10D is a configuration in which the insulating member 3 exposed to the receding portion 9 is completely removed. However, as shown in FIG. 1A, the insulating layer 3b may be partially removed. . The effects of the retreating portion 9 and the control electrode 13 in the configuration are the same as in the first invention described above. However, on the gate surface (XY plane) facing the anode 11, the length of the gate 5 in the direction (X direction) perpendicular to the edge on the side where the gate 5 faces the cathode 6 is T5x [m]. Sometimes it is necessary to satisfy:

T5 <5 × (Vf / Va) × (h / π)
T5x <5 × (Vf / Va) × (h / π)
Vf ≧ Vc

  Since the gate 5 is electrically insulated from the control electrode 13 and the cathode 6, the potential is formed on the substrate 1 by the conductive member 15 and a contact hole is formed in the insulating member 3 as shown in FIG. 10C. What is necessary is just to pull out out of an element by the done wiring.

〔Production method〕
A method for manufacturing an electron-emitting device according to the present invention will be described with reference to FIGS. 6A and 6B.

  6A and 6B are schematic views sequentially illustrating an example of a manufacturing process of the electron-emitting device illustrated in FIG. 1C.

  The substrate 1 is an insulating substrate for mechanically supporting the element, and is made of quartz glass, glass with reduced impurity content such as Na, blue plate glass, and a silicon substrate. The necessary functions of the substrate 1 are not only high mechanical strength, but also resistant to alkalis and acids such as dry or 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.

First, as shown in FIG. 6A, an insulating layer 23 to be the insulating layer 3a, an insulating layer 24 to be the insulating layer 3b, and a conductive layer 25 to be the gate 5 are stacked on the substrate 1. The insulating layers 23 and 24 are insulating films made of a material excellent in 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 layers 23 and 24 is set in the range of 5 nm to 50 μm, and preferably selected in the range of 50 nm to 500 nm. In addition, since it is necessary to form the recessed part 7 after laminating | stacking the insulating layers 23 and 24, you have to set so that it may have a different etching amount with respect to an etching between the insulating layer 23 and the insulating layer 24. FIG. Desirably, the selectivity between the insulating layer 23 and the insulating layer 24 is preferably 10 or more, and preferably 50 or more. Specifically, for example, Si _x N _y is used for the insulating layer 23, and an insulating material such as SiO ₂ is used for the insulating layer 24, or a PSG having a high phosphorus concentration, a BSG film having a high boron concentration, or the like is used. be able to.

The conductive layer 25 is formed by a general vacuum film forming technique such as vapor deposition or sputtering. As the conductive layer 25, a material having high thermal conductivity and high melting point in addition to conductivity is desirable. For example, metal or alloy material such as Be, Mg, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Al, Cu, Ni, Cr, Au, Pt, Pd, TiC, ZrC, HfC, TaC, Examples thereof include carbides such as SiC and WC. _{Further, HfB 2, ZrB 2, CeB} 6, YB 4, GdB borides such as _4, TiN, ZrN, HfN, nitride such as TaN, Si, a semiconductor such as Ge, an organic polymer material may also be used. Furthermore, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, a carbon compound, and the like can be cited, and are appropriately selected from these.

  Further, the thickness of the conductive layer 25 is set in the range of 5 nm to 500 nm, and is preferably selected in the range of 50 nm to 500 nm.

  Next, after a resist pattern is formed on the conductive layer 25 by photolithography, the conductive layer 25, the insulating layer 24, and the insulating layer 23 are sequentially processed using an etching method. Thereby, as shown to (b) of FIG. 6A, the insulating member 3 which consists of the gate 5, the insulating layer 3b, and the insulating layer 3a is obtained.

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 when the target member to be processed produces fluoride. 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, in order to obtain a selection ratio with the resist, hydrogen, oxygen, argon gas or the like is added at any time in order to ensure the smoothness of the etching surface or increase the etching speed.

  As shown in FIG. 6A (c), by using an etching technique, only a part of the side surface of the insulating layer 3b is removed on one side surface of the stacked body to form the recess 7.

Method for etching can be used a mixed solution of for example insulating layer 3b is ammonium fluoride and hydrofluoric acid, it referred to as long as the material of SiO ₂ called buffer hydrofluoric acid (BHF). If the insulating layer 3b is made of Si _x N _y, it can be etched with a hot phosphoric acid based etchant.

  The depth of the concave portion 7, that is, the distance between the side surface of the insulating layer 3b and the side surface of the insulating layer 3a and the gate 5 in the concave portion 7 (T6 in FIG. 1A) is deeply related to the leakage current after forming the element. The current value becomes smaller. However, if the recess 7 is formed too deep, problems such as deformation of the gate 5 occur, and therefore, the recess 7 is formed with a thickness of about 30 nm to 200 nm.

  In this example, the insulating member 3 is a laminated body of the insulating layers 3a and 3b. However, the present invention is not limited to this, and by removing a part of one insulating layer. The recess 7 may be formed.

  Next, a resist pattern is formed on the gate 5 in order to form the recess 9 again. The gate 5, the insulating layer 3 b, and the insulating layer 3 b are processed in this order using an etching method to form a recess 9 in the gate 5, and unnecessary portions of the insulating member 3 are removed.

  Next, as shown in FIG. 6A (d), a release layer 20 is formed on the surface of the gate 5. The purpose of forming the release layer 20 is to release the cathode material 26 deposited in the next step from the gate 5. For this purpose, the release layer 20 is formed by, for example, a method of oxidizing the gate 5 to form an oxide film, or attaching a release metal by electrolytic plating.

  After the constituent material of the control electrode 13 is formed on the surface of the insulating layer 3 exposed in the receding portion 9 and patterned, the cathode material 26 is placed on the substrate 1 and the side surface of the insulating member 3 as shown in FIG. 6B (e). Adhere. At this time, the cathode material 26 also adheres on the gate 5.

The control electrode 13 is formed by a general vacuum film forming technique such as vapor deposition or sputtering. Examples of the constituent material include metals such as Be, Mg, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Al, Cu, Ni, Cr, Au, Pt, and Pd, and TiC, ZrC. , HfC, TaC, SiC, WC and other carbides. _{Further, HfB 2, ZrB 2, CeB} 6, YB 4, GdB borides such as _4, TiN, ZrN, HfN, nitride such as TaN, Si, a semiconductor such as Ge, an organic polymer material may also be used. Furthermore, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, a carbon compound, and the like can be cited, and are appropriately selected from these.

  The thickness of the control electrode 13 is set in the range of 5 nm to 500 nm, and preferably selected in the range of 50 nm to 500 nm.

The cathode material may be any material that is conductive and field emission, and is generally a high melting point of 2000 ° C. or higher and a work function material of 5 eV or less, and it is difficult to form a chemical reaction layer such as an oxide. Or the material which can remove a reaction layer easily is preferable. Examples of such materials include metal or alloy materials such as Hf, V, Nb, Ta, Mo, W, Au, Pt, and Pd, carbides such as TiC, ZrC, HfC, TaC, SiC, and WC, HfB ₂ , and ZrB. ₂ , borides such as CeB ₆ , YB ₄ , and GdB ₄ . Examples thereof include nitrides such as TiN, ZrN, HfN, and TaN, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, and a carbon compound.

  As a method for depositing the cathode material 26, a general vacuum film forming technique such as vapor deposition or sputtering is used, and EB vapor deposition is preferably used.

The cathode material may be any material that is conductive and field emission, and is generally a high melting point of 2000 ° C. or higher and a work function material of 5 eV or less, and it is difficult to form a chemical reaction layer such as an oxide. Or the material which can remove a reaction layer easily is preferable. Examples of such materials include metal or alloy materials such as Hf, V, Nb, Ta, Mo, W, Au, Pt, and Pd, carbides such as TiC, ZrC, HfC, TaC, SiC, and WC, HfB ₂ , and ZrB. ₂ , borides such as CeB ₆ , YB ₄ , and GdB ₄ . Examples thereof include nitrides such as TiN, ZrN, HfN, and TaN, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, and a carbon compound.

  As a method for depositing the cathode material 26, a general vacuum film forming technique such as vapor deposition or sputtering is used, and EB vapor deposition is preferably used.

  As shown in FIG. 6B (f), the release layer 20 is removed by etching to remove the cathode material 26 on the gate 5. Moreover, the cathode material 26 on the substrate 1 and the side surface of the insulating member 3 is patterned by photolithography or the like to form the cathode 6. Further, in order to remove the cathode material adhering to the side wall of the second insulating layer 3b of the recess portion 7 and the recess portion 9, the same etching as that for producing the recess portion 7 is performed again.

Next, as shown in FIG. 6B (g), the electrode 2 is formed in order to establish electrical continuity with the cathode 6. The electrode 2 has conductivity similar to the cathode 6 and is formed by a general vacuum film forming technique such as a vapor deposition method or a sputtering method, or a photolithography technique. Examples of the material of the electrode 2 include metals such as Be, Mg, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Al, Cu, Ni, Cr, Au, Pt, and Pd, and TiC. , ZrC, HfC, TaC, SiC, WC and other carbides. _{Further, HfB 2, ZrB 2, CeB} 6, YB 4, GdB borides such as _4, TiN, ZrN, nitrides such as HfN, Si, a semiconductor such as Ge, an organic polymer material. Furthermore, amorphous carbon, graphite, diamond-like carbon, carbon in which diamond is dispersed, a carbon compound, and the like can be cited, and are appropriately selected from these.

  The thickness of the electrode 2 is set in the range of 50 nm to 5 mm, and is preferably selected in the range of 50 nm to 5 μm.

  The electrode 2, the gate 5 and the control electrode 13 may be the same material or different materials, and may be the same formation method or different methods, but the gate 5 is set in a range where the film thickness is smaller than that of the electrode 2. Therefore, a low resistance material is desirable.

  In the above manufacturing method, the release layer 20 is provided and the cathode material 26 on the gate 5 is removed. However, a configuration in which a protruding portion made of the cathode material 26 is formed on the gate 5 is also within the scope of the present invention. Such a protrusion is formed by depositing the cathode material 26 on the gate 5 without providing the release layer 20 on the gate 5 in the region corresponding to the cathode 6 or depositing the cathode material 26 without providing the release layer 20. After that, the cathode material 26 can be formed by patterning.

  Hereinafter, an image display apparatus provided with an electron source obtained by arranging a plurality of electron-emitting devices according to the present invention will be described with reference to FIG. 11A.

  In FIG. 11A, 31 is an electron source substrate, 32 is an X direction wiring, 33 is a Y direction wiring, and the electron source substrate 31 corresponds to the substrate 1 of the electron-emitting device described above. Further, 34 is an electron-emitting device according to the present invention, and 35 is a connection.

  The m X-directional wirings 32 are made of Dx1, Dx2,... Dxm, and can be made of a conductive metal or the like formed by using a vacuum deposition method, a printing method, a sputtering method, or the like. The material, film thickness, and width of the wiring 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 or the like formed using a vacuum deposition method, a printing method, a sputtering method, or the like. For example, the electron source substrate 31 on which the X-direction wiring 32 is formed is formed in a desired shape on the entire surface or a part thereof, and in particular, the film thickness is such that it can withstand the potential difference at the intersection of the X-direction wiring 32 and the Y-direction wiring 33. The material and the production method are appropriately set. The X direction wiring 32 and the Y direction wiring 33 are respectively drawn out as external terminals.

  The electrode 2 and the gate 5 are electrically connected by a connection 35 made of a conductive metal or the like and the m X-direction wirings 32, the n Y-direction wirings 33, and the like.

  The material constituting the wiring 32 and the wiring 33, the material constituting the connection 35 and the material constituting the electrode 2 and the gate 5 may be the same or partially different from each other.

  Which of the electrode 2 and the gate 5 is connected to the X-direction wiring 32 is not particularly limited and can be appropriately selected. In general, the X direction wiring 32 is connected to a scanning signal applying unit (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.

  An image display apparatus configured using such a simple matrix electron source will be described with reference to FIG. 11B. FIG. 11B is a schematic diagram illustrating an example of the display panel of the image display device, which is shown with a part cut away.

  In FIG. 11B, the same members as those in FIG. 11A are denoted by the same reference numerals. Reference numeral 41 denotes a rear plate to which the electron source substrate 31 is fixed. Reference numeral 46 denotes a face plate in which a fluorescent film 44 as a phosphor as a light emitting member and a metal back 45 as an anode 11 are formed on the inner surface of the glass substrate 43. .

  Reference numeral 42 denotes a support frame, and a rear plate 41 and a face plate 46 are attached to the support frame 42 via frit glass or the like to constitute an envelope 47. Sealing with frit glass is carried out by baking for 10 minutes or more in the temperature range of 400 to 500 ° C. in the air or in nitrogen.

  The envelope 47 includes the face plate 46, the support frame 42, and the rear plate 41 as described above. Here, since the rear plate 41 is provided mainly for the purpose of reinforcing the strength of the electron source substrate 31, if the electron source substrate 31 itself has sufficient strength, the separate rear plate 41 is not required. Can do.

  That is, the support frame 42 may be directly sealed on the electron source substrate 31, and the envelope 47 may be configured by the face plate 46, the support frame 42, and the electron source substrate 31. On the other hand, by installing a support body (not shown) called a spacer between the face plate 46 and the rear plate 41, a structure having sufficient strength against atmospheric pressure can be obtained.

  In such an image display device, in consideration of the emitted electron trajectory, the phosphor is aligned and arranged on the upper part of each electron-emitting device 34.

  FIG. 11C is a schematic diagram illustrating an example of the fluorescent film 44 used in the image display apparatus of FIG. 11B. In the case of a color phosphor film, the phosphor film 52 is preferably composed of a black conductive material 51 and a phosphor 52 called a black stripe shown in (a) or a black matrix shown in (b) depending on the arrangement of the phosphors 52.

  Next, a configuration example of a driving circuit for performing television display based on an NTSC television signal on a display panel configured using an electron source having a simple matrix arrangement will be described with reference to FIG. 11D.

  In FIG. 11D, 61 is an image display panel, 62 is a scanning circuit, 63 is a control circuit, and 64 is a shift register. 65 is a line memory, 66 is a synchronizing signal separation circuit, 67 is a modulation signal generator, and Vx and Va are DC voltage sources.

  The display panel 61 is connected to an external electric circuit via terminals Dx1 to Dxm, terminals Dy1 to Dyn, and a high voltage terminal Hv. The terminals Dx1 to Dxm have scanning signals for sequentially driving one row (N elements) of an electron source provided in the display panel, that is, an electron emitting element group arranged in a matrix of m rows and n columns. Is applied. On the other hand, to the terminals Dy1 to Dyn, a modulation signal for controlling the output electron beam of each element of the electron emission elements in one row selected by the scanning signal is applied.

  The high-voltage terminal Hv is supplied with a DC voltage of, for example, 10 [kV] from the DC voltage source Va, which gives sufficient energy to excite the phosphor to the electron beam emitted from the electron-emitting device. It is an acceleration voltage to do.

  As described above, an image display is realized by accelerating the emitted electrons and irradiating the phosphor with a scanning signal, a modulation signal, and application of a high voltage to the anode.

  By forming such a display device using the electron-emitting device of the present invention, a display device with a well-shaped electron beam can be configured, and as a result, a display device with good display characteristics can be provided. .

The following examples further illustrate the present invention (Example 1).
The electron-emitting device having the configuration shown in FIGS. 1A to 1D was manufactured along the steps of FIGS. 6A to 6B.

First, PD200, which is a low sodium glass developed for plasma displays, is used as the substrate 1, and SiN (Si _x N _y ) having a thickness of 500 nm and SiO ₂ having a thickness of 30 nm are formed by sputtering as the insulating layers 23 and 24. Formed. Next, TaN having a thickness of 30 nm was stacked as the conductive layer 25 by sputtering [FIG. 6A (a)].

  Next, after forming a resist pattern including comb-like protruding regions 12 and recesses 9 on the conductive layer 25 by photolithography technology, the conductive layer 25, the insulating layer 24, and the insulating layer 23 are formed using a dry etching technique. It processed in order [FIG. 6A (b)].

As the processing gas at this time, a CF ₄ -based gas was used because a material for forming a fluoride in the insulating layers 23 and 24 and the conductive layer 25 was selected. As a result of performing RIE using this gas, the angles of the insulating layers 3a and 3b and the side surfaces of the gate 5 after etching were formed at an angle of about 80 ° with respect to the horizontal plane of the substrate 1.

  After stripping the resist, the side surface of the insulating layer 3b is etched using BHF (hydrofluoric acid / ammonium fluoride aqueous solution) so that the depth T6 is about 70 nm, and the recess 7 [FIG. 6A (c)].

  Ni was electrolytically deposited on the surface of the gate 5 by electrolytic plating to form a release layer 20 [FIG. 6A (d)].

  Again, a resist pattern for forming the recess 9 is formed on the gate 5 by photolithography, and the gate 5 and the insulating layers 3a and 3b are sequentially processed using a dry etching technique to form the recess 9; A part of the insulating member 3 was removed.

  At this time, a comb-teeth-like process with a pitch of 6 μm was performed by setting the receding distance T8 of the comb-like receding portion 9 to 5 μm, the width T7 of the receding portion 9 and the width T5 of the protruding region 12 to 3 μm. The length of the electron-emitting device in the Y direction was 100 μm.

  After removing the resist, Ni was electrolytically deposited on the surface of the gate 5 by electrolytic plating to form a release layer 20 [FIG. 6A (d)].

  Molybdenum (Mo), which is the cathode material 26, was attached to the gate 5, the side surface of the insulating member 3, and the surface of the substrate 1. In this example, an EB vapor deposition method was used as a film forming method. In this forming method, the angle of the substrate 1 was set to 60 ° with respect to the horizontal plane. As a result, Mo was incident on the upper portion of the gate 5 at 60 °, and incident on the slope after the RIE processing of the insulating member 3 at an incident angle of 40 °. The deposition rate was determined so that the deposition was about 12 nm / min, and the Mo thickness on the slope was formed to be 30 nm by precisely controlling the deposition time for 2.5 minutes [FIG. 6B (e)].

  After the Mo film was formed, the Ni peeling layer 20 deposited on the gate 5 was removed using an etching solution composed of iodine and potassium iodide, thereby peeling the Mo film on the gate 5 [FIG. 6B (f)]. . At this time, since the release layer 20 was not formed on the surface of the insulating member 3 exposed in the receding portion 9, the cathode material 26 remained.

  BHF is again used so that the cathode material 26 and the gate 5 deposited on the surface of the insulating member 3 exposed to the receding portion 9 are electrically separated, and the cathode 6 and the gate 5 are electrically separated. Etching was performed. As a result, the cathode material 26 adhering to the side surface of the insulating layer 3b is lifted off and electrically separated.

  As a result of analysis by the cross-sectional TEM, the shortest distance T13 of the gap 8 between the cathode 6 and the gate 5 in FIG. 1C was 9 nm.

  Next, Cu having a thickness of 500 nm was deposited by sputtering and patterned to form an electrode 2 [FIG. 6 (g)].

  After the device was formed by the above method, the characteristics of the electron-emitting device were evaluated with the configuration shown in FIG.

  Here, the electron emission efficiency η is generally given by an efficiency η = Ie / (If + Ie) using a current If detected when a voltage is applied to the device and a current Ie taken out in vacuum.

  In this example, since the cathode 6 and the control electrode 13 are electrically connected, the potential difference Vc between the gate 5 and the control electrode 13 is equal to the potential difference Vf between the cathode 6 and the gate 5.

  When Va = 11.8 kV, Vf = Vc = 24 V, and h = 1.66 mm, the electron beam shape of this example was measured. As a result, the Y direction was 230 μm and the x direction was 130 μm.

(Comparative example)
Next, as shown in FIG. 8, an electron-emitting device having a similar form to that of Example 1 was prepared except that the gate 5 was not provided with the recess 9 and the control electrode 13 was not provided, and the effect was verified.

  The manufacturing process of the device of this example is the same as that of Example 1, but the receding portion 9 was not removed by etching, the gate 5 was processed into a straight line, and only the cathode 6 was formed in a strip shape.

  Using the electron source thus obtained, the same characteristic evaluation as in Example 1 was performed. When Va = 11.8 kV, Vf = Vc = 24 V, and h = 1.66 mm, the electron beam shape of this example was measured. As a result, the Y direction was 300 μm and the X direction was 120 μm.

(Example 2)
In the same manufacturing process as in Example 1, various elements having different widths T5 of the protruding regions 12 of the gate 5 having the configuration shown in FIG. 1A were manufactured, and the dependency of T5 was examined.

  In this example, Va = 11.8 kV, Vf = Vc = 24 V, h = 1.66 mm, and xs was about 1 μm. As T5 was made smaller, a decrease in the size of the electron beam in the Y direction was confirmed as T5 became smaller than a certain value. This is shown in FIG. The horizontal axis is T5 / xs. It was found that a focusing effect on the size of the electron beam in the Y direction appears at T5 / xs <5.

  The beam size in the Y direction when T5 = 100 μm was about 300 μm, but the beam size in the Y direction gradually decreased as T5 was decreased to 9 μm, 5 μm, 3 μm,.

(Example 3)
An electron-emitting device having the configuration shown in FIG. 10A was produced. In this example, T5 = T5x = 5 μm.

  Since the basic manufacturing process is the same as that of the first embodiment, only the difference from the first embodiment will be described here.

  In this example, a wiring (not shown) for supplying a potential to the gate 5 is provided under the insulating layer 3a, contact holes penetrating the insulating layers 3a and 3b and the gate 5 are formed, and then a cathode forming material is formed. Then, contact was made between the gate 5 and the wiring in the cathode forming step. The contact hole was 1 μm in each of the X and Y directions.

  After forming the element by the above method, the beam shape was evaluated in the same manner as in Example 1.

  When Va = 11.8 kV, Vf = Vc = 24 V, and h = 1.66 mm, the electron beam shape of this example was measured. As a result, the Y direction was 230 μm and the X direction was 70 μm.

  From this result, it was found that the beam focusing effect by the rotating electric field can be obtained not only in the Y direction but also in the X direction in the configuration of this example.

Example 4
In this example, an electron source substrate is formed by arranging a large number of electron-emitting devices in a matrix on a substrate by the same manufacturing method as the electron-emitting device manufactured in Example 1 of the present invention described above. The image display device shown in FIG. 11B was manufactured using the substrate. As the substrate 41, the substrate 31 was used as it was. The manufacturing process of the image display device of this example will be described below.

<Electrode production process>
After sequentially forming a SiN / SiO ₂ / TaN / Mo film on the glass substrate 31, a recess 7 is formed by the same manufacturing method as the electron-emitting device of Example 1, and further, a step having a recess 9 is etched. processed. In this example, T5 = T7 = 3 μm, and 17 cathodes 6 are arranged per element having an element length of 100 μm in the Y direction.

<Cathode formation>
Molybdenum (Mo), which is a cathode material, was deposited on the gate 5. In this example, the EB vapor deposition method was used as the film formation method, and the angle of the substrate 31 was set to 60 °. Thus, Mo was incident on the upper part of the gate 5 at 60 °, and the incident angle was set to 40 ° on the slope after the RIE processing of the insulating layer 3a (SiN) of the element. Vapor deposition was performed at a deposition rate of about 10 nm / min for 4 minutes. By precisely controlling the deposition time, the slope Mo was formed to a thickness of 40 nm.

  Thereafter, the same etching as that for forming the recess 7 was performed, and the gate 5, the cathode 6 and the control electrode 13 were electrically separated to form an electron-emitting device.

<Y direction wiring formation process>
Next, the Y-direction wiring 33 is arranged so as to be connected to the gate 5. The Y-direction wiring 33 functions as a wiring to which a modulation signal is applied.

<Insulating layer formation process>
Next, an insulating layer made of silicon oxide is disposed in order to insulate the X-direction wiring 32 created in the next step from the Y-direction wiring 33 described above. An insulating layer is disposed so as to cover the Y-direction wiring 33 formed earlier and below the X-direction wiring 32 described later. A contact hole was formed in a part of the insulating layer so that the X-direction wiring 32 and the electrode 2 could be electrically connected.

<X direction wiring formation process>
Next, an X-direction wiring 32 mainly composed of silver was formed on the previously formed insulating layer. The X-direction wiring 32 intersects the Y-direction wiring 33 with the insulating layer interposed therebetween, and is connected to the electrode 2 at the contact hole portion of the insulating layer. The X direction wiring 32 functions as a wiring to which a scanning signal is applied. In this way, a substrate having matrix wiring was formed.

  Next, as shown in FIG. 11B, a face plate 46 in which the phosphor film 44 and the metal back 45 are laminated on the inner surface of the glass substrate 43 is disposed 2 mm above the substrate 31 via the support frame 42. .

  And the joint part of the face plate 46, the support frame 42, and the board | substrate 31 was sealed by heating and cooling indium (In) which is a low melting metal. Moreover, since this sealing process was performed in a vacuum chamber, sealing and sealing were performed simultaneously without using an exhaust pipe.

  In this example, the fluorescent film 44 serving as an image forming member is a stripe-shaped phosphor to realize color, and a black stripe (not shown) is formed first, and each color is formed by a slurry method in the gap portion. A phosphor (not shown) was applied to produce a phosphor film 44. As the material for the black stripe, a material mainly composed of graphite, which is commonly used, was used.

  In addition, a metal back 45 made of aluminum was provided on the inner surface side (electron emitting element side) of the fluorescent film 44. The metal back 45 was produced by vacuum-depositing Al on the inner surface side of the fluorescent film 44.

  When an image display device was manufactured by the above-described steps, a display device having a good display image could be realized.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Electrode 3 Insulating member 3a, 3b Insulating layer 5 Gate 6 Cathode 7 Recessed part 8 Gap 9 Recessed part 11 Anode 12 Protruding area 13 Control electrode

Claims (5)

An insulating member having a recess on the surface;
A gate located on the surface of the insulating member;
At least one cathode located on the surface of the insulating member so as to project from the edge of the recess toward the gate, the projecting portion facing the gate;
An anode disposed opposite to the protruding portion with the gate interposed therebetween;
The gate is formed on the surface of the insulating member so that a region facing the cathode protrudes, and a gate end portion of a region sandwiching the protruding region has a retreated portion,
Retreat until the surface of the insulating member facing the anode through the receding portion reaches at least the edge on the cathode side of the recess, and a control electrode is disposed in a region facing the anode through the receding portion,
The voltage applied between the cathode and the gate is Vf [V], the voltage applied between the control electrode and the cathode is Vc [V], and the voltage applied between the anode and the cathode is Va [V]. ] When the distance from the surface opposite to the side where the gate of the insulating member is disposed to the anode is h [m], and the width of the protruding region of the gate is T5 [m],
T5 <5 × (Vf / Va) × (h / π)
Vf ≧ Vc
An electron beam apparatus characterized by   The electron beam apparatus according to claim 1, wherein the electron beam apparatus has two or more cathodes, and the gate is formed in a comb-teeth shape on the surface of the insulating member. An insulating member having a recess on the surface;
A gate located on the surface of the insulating member;
At least one cathode located on the surface of the insulating member so as to project from the edge of the recess toward the gate, the projecting portion facing the gate;
An anode disposed opposite to the protruding portion with the gate interposed therebetween;
The surface of the insulating member on the side where the gate is disposed has a receding portion that recedes at least around the cathode side edge of the concave portion around the gate;
A control electrode is disposed on the surface of the receding portion;
The voltage applied between the cathode and the gate is Vf [V], the voltage applied between the control electrode and the cathode is Vc [V], and the voltage applied between the anode and the cathode is Va [V]. ] The distance from the surface of the insulating member opposite to the side where the gate is disposed to the anode is h [m], the width of the region facing the cathode of the gate is T5 [m], and the gate surface facing the anode When the length of the gate in the direction orthogonal to the edge on the side facing the cathode is T5x [m],
T5 <5 × (Vf / Va) × (h / π)
T5x <5 × (Vf / Va) × (h / π)
Vf ≧ Vc
An electron beam apparatus characterized by   4. The electron beam apparatus according to claim 3, wherein two or more sets of the cathode and the gate facing the cathode are spaced apart from each other.   An image display device comprising: the electron beam device according to claim 1; and a light emitting member positioned outside the anode.

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