JP2010186655A - Electron beam device and image display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electron beam device equipped with an electron-emitting element of simple configuration with high electron emission efficiency and of stable operation, and with a high electron convergence rate to an anode. <P>SOLUTION: An insulating member 3 and a gate 5 are formed on a substrate 1, a recess 7 is formed on the insulating member, and a cathode 6 is arranged on a side surface of the insulating member 3. The gate 5 is so arranged to form an uneven shape having regions corresponding to the cathode 6 projected outward and recessed portions 9 with end portions of the gate on both sides of the regions recessed. <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 having a simple configuration, high electron emission efficiency, stable operation, and high electron arrival efficiency to the anode, and an image display apparatus using the electron beam apparatus Is to provide.

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 at least a part of a region facing the cathode protrudes, and a gate end portion recedes across the protruding region. It is an electron beam device.

  The electron beam apparatus of the present invention includes the following configuration as a preferred embodiment.

The width of the protruding region of the gate is T5 [m], the width of the cathode is T4 [m], the shortest distance between the protruding portion of the cathode and the gate is T13 [m], and the protruding region of the gate is the region facing the cathode When the length of the protruding part is T12 [m],
T5> T4
T12 <T13
It is.

The height of the recess in the stacking direction of the gate and the insulating member is T2 [m], the receding distance of the receding portion is T8 [m], the work function of the cathode is Wf [eV], and the voltage applied between the cathode and the gate When the energy when one electron is accelerated by Vf [V] is EVf [eV],
T8 ≧ 6 × T2 × {1- (Wf / EVf)}
It is.

  Two or more cathodes are provided, and a gate is formed in a comb shape on the surface of the insulating member.

  At least a part of the insulating member corresponding to the receding portion of the gate is formed such that the surface recedes in the same manner as the receding portion.

  According to a second aspect of the present invention, there is provided an image display device comprising the electron beam device according to the present invention and a light emitting member positioned outside the anode.

  According to the present invention, since the gate is provided with the receding portion, collision of the emitted electrons to the gate bottom surface is reduced, and the electron emission efficiency of the electrons is improved. Therefore, in the image display apparatus using the electron beam apparatus of the present invention, a high quality image can be stably displayed.

It is a perspective view which shows typically the structure of one Embodiment of the electron-emitting element of the 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 plane schematic diagram of the electron-emitting device of FIG. 2A. It is a cross-sectional schematic diagram of the electron-emitting device of FIG. 2B. It is a schematic diagram which shows the locus | trajectory of the discharge | released electron in the electron emission element of a structure which does not provide a recessed part in a gate. It is a schematic diagram which shows the locus | trajectory of the emission electron in the electron emission element of FIG. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency. It is a schematic diagram which shows the mean free path of electrons between parallel plate electrodes. FIG. 4 is an enlarged schematic view around a gap between a cathode and a gate. It is a perspective view which shows the other structure of the electron-emitting element of the electron beam apparatus of this invention. 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 graph which shows the relationship between receding distance T8 and electron emission efficiency in the Example of this invention. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency for every Vf in the Example of this invention. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained for every driving voltage Vf. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained for every gate height T1. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained for every work function Wf of the cathode. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained for every height T2 of a recessed part. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained for every height T3 of the insulating layer 3a. It is a graph which shows the relationship between retreat distance T8 and electron emission efficiency which were obtained by simulation for every distance T7 between cathodes. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained for every anode applied voltage Va. It is a graph which shows the relationship between the distance T12 which the protrusion area | region of the gate protruded from the opposing area | region with a cathode, and electron emission efficiency obtained by simulation. It is a perspective view which shows the other structure of the electron-emitting element of the electron beam apparatus of this invention. It is a graph which shows the relationship between receding distance T8 and electron emission efficiency obtained by simulation for every height T11 of the side surface in which the 1st insulating layer 3a made it recede. It is the graph which compared the relationship between the saturation amount Lsat of retreat distance, and the drive voltage Vf by the calculation result by simulation, and the value obtained from a calculation formula. It is the graph which compared the relationship between the amount of saturation Lsat of retreat distance, and the height T2 of the recessed part by the calculation result by simulation, and the value obtained from a calculation formula. It is the graph which compared the relationship between the saturation amount Lsat of retreat distance, and the work function Wf by the calculation result by simulation, and the value obtained from a calculation formula. It is a schematic diagram which shows the other structure of the electron-emitting element of the electron beam apparatus of this invention. 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. FIG. 26B is a schematic diagram illustrating a configuration example of a driving circuit for performing television display based on an NTSC television signal on a display panel configured using the electron source illustrated in FIG. 26A.

  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 electron beam apparatus of the present invention. FIG. 1A is a perspective view, FIG. 1B is a plan view, and FIG. 1C is an AA in FIG. 'Cross-sectional view, FIG. 1D is a cross-sectional view along BB' 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 shows an example having two.

  The gate 5 has at least a part of a region facing the cathode 6 and an end portion having an uneven shape that becomes a retreating portion 9 in which the gate end portions of both sides sandwiching the protruding region 12 (protruding region) are retreated. Thus, it is formed on the surface of the insulating member. 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. In this example, the width T5 of the protruding region 12 sandwiched between the retreating portions 9 of the gate 5 is equal to the width T4 of the cathode 6.

  In the electron-emitting device of FIGS. 1A to 1D, the side surface of the insulating member 3 corresponding to the retreating portion 9 of the gate 5 is not retreated inward like the retreating portion 9, but the present invention is not limited to this. For example, as shown in FIG. 2A to FIG. 2C, the insulating member 3 corresponding to the receding portion 9 (overlapping the receding portion 9) may be formed so that the side surface recedes inward, like the receding portion 9. . Further, as shown in FIG. 20, only a part of the insulating member 3 (above the insulating layers 3b and 3a in FIG. 20) is formed so as to be recessed so that the end part is retracted inward, similarly to the receding part 9. You may do it. 2A and 20 are respectively perspective views of the embodiment of the present invention, FIG. 2B is a plan view of FIG. 2A, and FIG. 2C is a cross-sectional view along B-B ′ of FIG. 2B.

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)
T4: Width of the cathode 6 (the length of the cathode 6 in the direction parallel to the opposite ends of the gate 5 and the cathode 6 (Y direction))
T5: width of the protruding region 12 of the gate 5 (the length of the protruding region 12 in the direction (Y direction) parallel to the opposite edges 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: Distance between the cathodes 6 when a plurality of cathodes 6 are provided T8: Retreat distance of the receding portion 9 (the side surface facing the cathode 6 of the gate 5 and the side surface of the receding portion 9 (side surface at the most receded position)) Distance or length of the protruding region 12 of the gate 5 in the X direction)
T13: The shortest distance between the cathode tip and the gate

[Operation of the retreating portion 9]
The operation of the retreating portion 9 in the present invention will be described. 3A is an element in which the retreating portion 9 is not provided and the gate 9 is widened with respect to the cathode 6 (T4 <T5), and FIG. 3B is an electrode in which the cathode 6 and the gate 5 of the element in FIG. The enlarged schematic diagram seen from 2 side is shown.

  As shown in FIG. 3A, when the retreating portion 9 is not provided and the gate 5 is wider than the cathode 6 in the region facing the cathode 6, electrons emitted from the vicinity of the end in the width direction of the cathode 6 are As indicated by a broken line, the light isotropically scatters at the bottom surface 5b of the gate 5. Then, some of the scattered electrons collide with the gate 5 again and repeat scattering.

  On the other hand, in the present invention, as shown in FIG. 3B, when the retreating portions 9 are formed on both sides of the region facing the cathode 6 of the gate 5, the retreating portion 9 does not have the gate 5; Compared to the configuration of 3A, collision scattering of electrons on the bottom surface 5b of the gate 5 is reduced. Therefore, in the said structure, the electron which flies to the anode side via the retreat part 9 increases, and the electron emission efficiency of an emitted electron improves.

[Reverse distance T8]
The retreat distance T8 of the retreat portion 9 is as large as possible, and the region where electrons collide is reduced. Therefore, it is clear that this contributes to the improvement of the electron emission efficiency. From the viewpoint of shortening the tact time, a smaller one is advantageous. Therefore, FIG. 4 shows a result of calculating the relationship between the receding distance T8 of the receding portion 9 of the gate 5 and the electron emission efficiency by simulation.

  In FIG. 4, the abscissa indicates the receding distance T8 of the receding portion 9, and the ordinate indicates the electron emission efficiency. As can be seen from FIG. 4, the electron emission efficiency increases as the receding distance T8 of the gate 5 increases, but is saturated at a certain value or more. This shows that if the retreating part 9 having a certain size is provided, the number of electrons flying to that extent is reduced, and therefore, even if the retreating distance T8 is further increased, the effect of improving the electron emission efficiency is lost. ing.

  Here, let Lsat be the minimum receding distance T8 at which the increase in electron emission efficiency is saturated, and an expression representing Lsat will be examined.

  First, considering the case where there is no retreating portion 9 (T8 = 0), some of the electrons emitted from the cathode 6 are collided and scattered on the bottom surface 5b of the gate 5 and fly between the recesses 7. The mean free path of electrons at this time is derived as follows, assuming a uniform electric field with a driving voltage Vf on parallel plates.

First, as shown in FIG. 5, a uniform electric field is obtained in which the potentials of V = 0 [V] and V = Vf [V] are applied to the two electrodes 21 and 22 separated by a distance h on the xy plane, respectively. . Here, let us consider the flight distance of electrons after electrons emitted from a position offset from the electrode 21 side of V = 0 [V] by the work function Wf [eV] collide with the V = Vf side and are scattered. Charge amount e [C] of one electron, mass m [kg] of one electron, kinetic energy K [kg · m ² / s ² ] of one electron, electric field intensity E [V / m], electron velocity Magnitude v [m / s], electron acceleration a [m / s ² ], electron x-direction velocity vx [m / s], y-direction velocity vy [m / s], and one electron with potential difference Vf When energy EVf [eV] = e × Vf when accelerated is given,
K = (1/2) × m × v ² (1)
ma = eE (2)
From (1) and (2),
v = (2K / m) ^1/2 (3)
a = eE / m (4)
Y-direction displacement y (t) at time t = vy × t + (1/2) × a × t ² (5)
x-direction displacement x (t) = vx × t (6)
From (5), t = −2 × (vy / a) where y (t) = 0 (7)
Substituting (7) into (6), x = −2 × vx × (vy / a) (8)
In (8), x is maximum when vx = v / 2 ^1/2 and vy = −v / 2 ^1/2 ,
x = v × (v / a) = (2 × K / m) / (eE / m) = 2K / (e × E) (9)
If E = Vf / h and K = EVf−Wf,
x = 2 * h * {1- (Wf / EVf)} (10)
It becomes.

When the retreating portion 9 is provided, the electric field is weakened, so that the electrons fly farther. The effect due to the weakening of the electric field by providing the retreat part 9 is defined as a coefficient α, and the average flight distance is x ′ = α × x = 2α × h × {1− (Wf / EVf)} (11)
It becomes.

In the equation (11), h corresponds to the height T2 of the insulating layer 3b, and the value of α is reasonable to be about 3 from the examination results so far. After all, the value of the saturation amount Lsat of the receding distance T8 is Lsat = 6 * T2 * {1- (Wf / EVf)} (12)
Can be expressed as

That is, in order to sufficiently obtain the effect of increasing the electron emission efficiency,
It is desirable that T8 ≧ 6 × T2 × {1- (Wf / EVf)}.

[T4 and T5]
In the above description, the configuration in which the width T4 of the cathode 6 is equal to the width T5 of the protruding region 12 of the gate 5 has been described, but the effect of increasing the electron emission efficiency can be obtained even when T4> T5. This is apparent from the action of the retreating portion 9 described above.

  However, when T5> T4, the electrons emitted from the cathode 6 are repeatedly scattered by the amount that the width of the gate 5 is wider than that of the cathode 6 before reaching the receding portion 9 of the gate 5, thereby increasing the electron emission efficiency. It is considered that the effect of is difficult to obtain.

  From the above examination, in order to obtain the effect of increasing the electron emission efficiency, the shortest distance of the gap 8 shown in FIG. 1C is T13, and the protruding region 12 of the gate 5 shown in FIG. It is desirable that T12 <T13, where T12 is T12.

  In the above description, the corner when the recess 7 is provided in the gate 5 or the insulating member 3 is shown as a right angle. However, as shown by 10 in FIG. 7, the corner may be rounded (R portion). . However, even in the configuration as shown in FIG. 7, the minimum receding distance T8 at which the increase in the electron emission efficiency is saturated is expressed by the above-described equation (12).

That is, the receding distance T8 ′ at the position where the side wall of the gate 5 is most receded in FIG.
It is desirable that T8 ′ ≧ 6 × T2 × {1- (Wf / EVf)}.

〔Production method〕
A method of manufacturing the electron-emitting device according to the present invention described above will be described with reference to FIGS. 8A and 8B.

  8A and 8B 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. 8A (a), 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. 8A, 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. 8A (c), by using an etching method, 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. 8A (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.

  As shown in FIG. 8B (e), the cathode material 26 is attached to the substrate 1 and the side surface of the insulating member 3. At this time, the cathode material 26 also adheres on the gate 5.

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 described above, in the present invention, the cathode 6 is manufactured by controlling the deposition angle, the film formation time, the temperature at the time of formation, and the degree of vacuum at the time of formation so that the cathode 6 has an optimum shape in order to efficiently extract electrons. There is a need.

  As shown in FIG. 8B (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.

Next, as shown in FIG. 8B (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 and the gate 5 may be made of the same material or different materials, and may be formed by the same forming method or different methods. However, the gate 5 may be set in a range where the film thickness thereof is smaller than that of the electrode 2. Resistive 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, as shown in FIG. 25, a configuration in which a protruding portion 30 made of the cathode material 26 is formed on the gate 5 is also possible. This is within the scope of the present invention. Such protruding portions 30 are 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. Then, the cathode material 26 can be formed by patterning.

  Hereinafter, an image display apparatus including an electron source obtained by arranging a plurality of electron-emitting devices according to the present invention will be described with reference to FIG. 26A.

  In FIG. 26A, 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 device configured using such a simple matrix electron source will be described with reference to FIG. 26B. FIG. 26B is a schematic diagram illustrating an example of the display panel of the image display device, which is shown with a part thereof cut away.

  In FIG. 26B, the same members as those in FIG. 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. 26C is a schematic diagram illustrating an example of the fluorescent film 44 used in the image display apparatus of FIG. 26B. 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 driver circuit for performing television display based on NTSC television signals on a display panel configured using an electron source with a simple matrix arrangement will be described with reference to FIG. 26D.

  In FIG. 26D, 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. .

Example 1
The electron-emitting device having the configuration shown in FIGS. 1A to 1D was fabricated along the steps of FIGS. 8A to 8B.

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. 8A (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. Processed in order. At this time, the receding distance T8 was set to 100 nm, the distance T7 between the cathodes 6, the width T4 of the cathodes 6, and the width T5 of the protruding regions 12 were set to 5 μm, respectively, and comb-like processing with a pitch of 10 μm was performed [FIG.

Further, as the processing gas at this time, 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. 8A (c)].

  Ni was electrolytically deposited on the surface of the gate 5 by electrolytic plating to form a release layer 20 (FIG. 8A (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 30 nm by precisely controlling the deposition time for 2.5 minutes [FIG. 8B (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. 8B (f)]. .

Next, a resist pattern was formed by photolithography so that the width T4 of the cathode 6 was 5 μm. Thereafter, the Mo film on the substrate 1 and the side surface of the insulating layer 3a was processed using a dry etching method to form the cathode 6. As the processing gas at this time, CF ₄ -based gas was used because molybdenum used as the cathode material 26 forms a fluoride.

  As a result of analysis by a cross-sectional TEM (transmission electron microscope), the shortest distance T13 of the gap 8 between the cathode 6 and the gate 5 was 9 nm.

  Next, Cu having a thickness of 500 nm was deposited by sputtering and patterned to form an electrode 2 [FIG. 8B (g)].

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

  The configuration of FIG. 9 shows a power supply arrangement when measuring the electron emission characteristics of the device according to the present invention. As shown in FIG. 9, in the electron beam apparatus of the present invention, the anode 11 is disposed opposite to 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. 9, Vf is a voltage applied between the gate 5 and 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.

  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.

  As a result of evaluating the characteristics of the device of this example with the configuration shown in FIG. 9, an average electron emission current Ie of 1.5 μA and an average electron emission efficiency of 14% were obtained at a driving voltage of 26V.

(Comparative Example 1)
Next, an electron-emitting device was fabricated in the same manner as in Example 1 except that the recess 5 was not provided in the gate 5 and a region corresponding to the recess 9 was left in the insulating member 3. The cathode 6 was strip-shaped as in Example 1.

  Using the electron-emitting device thus obtained, the same characteristic evaluation as in Example 1 was performed. As a result, an electron emission current Ie of approximately 0.8 μA and an electron emission efficiency of approximately 9% on average were obtained at a driving voltage of 26V. There wasn't.

(Example 2)
An electron-emitting device was fabricated in the same manner as in Example 1 except that T8 was changed, and the T8 dependence of the electron emission efficiency was examined.

  As a result, an increase in electron emission efficiency was confirmed as T8 increased, but the effect gradually decreased and a tendency to saturate to a certain value was confirmed. This is shown in FIG.

  Although the electron emission efficiency when T8 = 0 was about 8%, it gradually increased as T8 was increased to 20 nm, 40 nm, 60 nm, etc., and T8 was increased to about 14% at 80 nm, further increasing T8. However, the increase in efficiency is no longer seen.

  Next, the dependence of the electron-emitting device driving voltage at T8 similar to the above was examined. As a result, as shown in FIG. 11, although the emission efficiency is lower as the drive voltage is lower, the increase in efficiency is saturated at a smaller T8, and the emission efficiency is higher and T8 at which the increase in efficiency is saturated increases as the drive voltage is higher. It was in.

(Examination by simulation)
Calculations by simulation were performed on the results shown in Example 1, Comparative Example, and Example 2, and the effects of the present invention were confirmed.

  In the following calculation, unless otherwise specified, T1 = 30 nm, T2 = 30 nm, T3 = 500 nm, T4 = T5 = 5 μm, T6 = 70 nm, and T7 = 3 μm. The driving voltage Vf = 24 V, the anode applied voltage = 11.8 kV, and the work function Wf = 4.6 eV.

[Change T8]
FIG. 4 shows the calculation result when T8 is changed in the range of 0 nm to 120 nm.

  As shown in FIG. 4, when the receding distance T8 is increased, the electron emission efficiency increases, but the efficiency is substantially constant above a certain amount. If the receding distance T8 at which the efficiency is substantially constant is Lsat, Lsat in FIG. 4 can be read as about 65 nm.

  In the calculation results shown in FIG. 4, Table 1 shows the number of arrivals of the anode for each number of electron scattering times.

  As can be seen from Table 1, when the receding distance T8 is increased, the number of electrons that reach the anode after one-time scattering increases, and the increase in one-time scattered electrons contributes to an increase in efficiency. That is, it can be confirmed that the electrons emitted from the cathode 6 once collide with the gate 5 and then reach the anode through the receding portion 9 without colliding again.

  From the above, it has been confirmed that the electron emission efficiency is increased by providing the gate 5 with the recess 9.

  Next, when the value of the minimum receding distance Lsat at which the increase in electron emission efficiency saturates changes the shape of the gap 8 between the cathode 6 and the gate 5 from which electrons are emitted, the driving voltage, and the material of the cathode 6, the efficiency increase increases. A study was made on how the value of the saturated Lsat changes. Specifically, how the value of Lsat changes when T1, T2, T3, T4, T5, drive voltage Vf, work function Wf of cathode 6 and anode applied voltage Va are changed independently. Was examined by simulation.

[Relationship between T8 and Vf]
FIG. 12 shows the calculation result when the drive voltage Vf is changed in the range of 12 to 48V. In FIG. 12, the horizontal axis represents the receding distance T8, and the vertical axis represents the electron emission efficiency. From FIG. 12, it can be seen that the receding distance Lsat at which the electron emission efficiency is constant differs depending on the value of the driving voltage Vf. It can be seen from FIG. 12 that when the drive voltage Vf = 12 V, Lsat = 40 nm, when the drive voltage Vf = 24 V, Lsat = 65 nm, and when the drive voltage Vf = 48 V, Lsat = 100 nm.

[Relationship between T8 and T2]
FIG. 13 shows the calculation result when the height T2 of the recess 7 is changed in the range of 20 nm to 35 nm. The horizontal axis is the receding distance T8, and the vertical axis is the electron emission efficiency. FIG. 13 shows that the value of the receding distance Lsat at which the electron emission efficiency is constant varies depending on the value of the height T2 of the recess 7. It can be seen from FIG. 13 that Lsat = 90 nm when T2 = 20 nm, and Lsat = 120 nm when T3 = 35 nm.

[Relationship between T8 and Wf]
FIG. 14 shows the calculation result when the work function Wf of the constituent material of the cathode 6 is changed in the range of 3.0 eV to 6.0 eV. In FIG. 14, the horizontal axis represents the receding distance T8, and the vertical axis represents the electron emission efficiency. In the calculation result shown in FIG. 14, the drive Vf is 12V. FIG. 14 shows that the value of the receding distance Lsat at which the electron emission efficiency is constant differs depending on the value of the work function. It can be seen from FIG. 14 that Lsat = 70 nm when the work function is 3.0 eV, Lsat = 50 nm when the work function is 4.5 eV, and Lsat = 30 nm when the work function is 6.0 eV.

[Relationship between T8 and T1]
FIG. 15 shows the calculation result when the height T1 of the gate 5 is changed in the range of 10 nm to 50 nm. The horizontal axis is the receding distance T8, and the vertical axis is the electron emission efficiency. FIG. 15 shows that there is no significant change in the receding distance Lsat where the electron emission efficiency is constant depending on the value of the height T1 of the gate 5.

[Relationship between T8 and T3]
FIG. 16 shows a calculation result when the distance (height of the insulating layer 3a) T3 from the recess 7 to the substrate 1 is changed in the range of 130 nm to 1 μm. The horizontal axis is the receding distance T8, and the vertical axis is the electron emission efficiency. FIG. 16 shows that there is no significant change in the receding distance Lsat at which the electron emission efficiency is constant depending on the distance from the recess 7 to the substrate 1.

[Relationship between T8 and T7]
FIG. 17 shows the calculation result when the distance T7 between the cathodes 6 is changed between 750 nm and 5 μm. The horizontal axis is the receding distance T8, and the vertical axis is the electron emission efficiency. FIG. 17 shows that there is no significant change in the receding distance Lsat at which the electron emission efficiency is constant depending on the value of T7.

[Relationship between T8 and Va]
FIG. 18 shows the calculation result when the anode applied voltage Va is changed in the range of 1 kV to 11.8 kV. The horizontal axis is the receding distance T8, and the vertical axis is the electron emission efficiency. FIG. 18 shows that there is no significant change in the receding distance Lsat where the electron emission efficiency becomes constant depending on the value of the anode applied voltage Va.

[Relationship between T4 and T5]
Up to this point, the calculation results for the case where the width T4 of the cathode 6 is equal to the width T5 of the protruding region of the gate 5 facing the cathode 6, that is, T12 = 0 in FIG. In the case of T4 ≧ T5, it can be said that there is an effect of increasing the electron emission efficiency by providing the receding portion 9 based on the results shown so far. Hereinafter, a case where T5> T4, that is, T12> 0 was examined.

  FIG. 19 shows a calculation result when the receding distance T8 is 115 nm, the shortest distance T13 between the cathode 6 and the gate 5 is 12 nm, and the value of T12 is changed in the range of 0 to 35 nm. The horizontal axis is T12, and the vertical axis is the electron emission efficiency. FIG. 19 shows that the electron emission efficiency decreases as the value of T12 is increased. It can be seen that it is desirable to satisfy T12 <T13 in order to provide the receding portion 9 to obtain the effect of increasing the electron emission efficiency.

[Configuration of FIGS. 2A and 20]
Up to this point, the results of the configuration in which the side surface of the insulating member 3 corresponding to the receding portion 9 of the gate 5 shown in FIG. 2A is also receded are shown. .

  Therefore, the side surface of the insulating member 3 is not retracted as shown in FIG. 1A, and the retracted portion 9 is provided only on the gate 5, or the first insulating layer 3a is somewhat elevated from the substrate surface as shown in FIG. We examined the remaining structure by simulation.

  In the configuration of FIG. 20, the receding distance T8 is set to 115 nm, and the height T11 of the portion of the first insulating layer 3a shown in FIG. 20 with the side receding corresponding to the receding portion 9 is changed in the range of 0 to 500 nm. FIG. 21 shows the calculation result when this is done. The horizontal axis is the receding distance T8, and the vertical axis is the electron emission efficiency. T11 = 0 means the case where the side surface of the second insulating layer 3b is retreated in FIG. 20, and the side surface of the first insulating layer 3a is not retreated, and T11 = 500 nm is the first insulation as shown in FIG. 2A. It means a configuration in which the side surfaces of the layer 3a are all receded. Retreating only the gate means a case where T11 = 0 and the second insulating layer 3b is not retracted.

  As shown in FIG. 21, even when T11 = 0 in which the side surface of the first insulating layer 3a is not retracted at all, it can be seen that the electron emission efficiency can be increased by retracting the side surface of the second insulating layer 3b. Further, it can be seen that even when the second insulating layer 3b is not retracted and only the gate 5 is provided with the recess, the electron emission efficiency can be expected to increase. Also, the receding distance Lsat at which the electron emission efficiency is constant tends to be slightly smaller when T11 = 0 than when T11> 0 or when only the gate 5 is retracted, but in the range of T11 ≧ 10 nm, There is no significant difference in values.

[Comparison of Lsat formula and simulation results]
From the above calculation results, the parameter for changing the receding distance Lsat necessary for sufficiently increasing the electron emission efficiency is the work function Wf or T5 when the condition of T12 <T13 is satisfied when T4 ≧ T5 or T5> T4. It can be seen that the driving voltage Vf is the height T2 of the recess 7.

As a formula representing the retreat distance Lsat, the formula (11) described above is used by using Wf, Vf, and T2.
Lsat = 6 × T2 × {1- (Wf / EVf)} (11)
FIG. 22, FIG. 23, and FIG. 24 show the relationship between the backward distance Lsat obtained by the calculation formula (11) and the backward distance Lsat _sim calculated by the simulation.

In FIG. 22, the horizontal axis represents Vf, the vertical axis represents the receding distance Lsat, the work function Wf = 4.6 eV, and the height T2 of the recess 7 = 20 nm. In any value of Vf = 12V to 48V, Lsat> Lsat _sim is satisfied, and if the amount of the retreating portion 9 obtained by the calculation formula (11) is provided, the effect of sufficiently increasing the electron emission efficiency can be obtained. Recognize.

Similarly, FIG. 23 is a diagram in which the horizontal axis represents the height T2 of the recess 7 and the vertical axis represents the retreat distance Lsat, where Vf = 24V and work function Wf = 4.6eV. For both values of T2 = 20 nm and 35 nm, Lsat> Lsat _sim is satisfied, and if the amount of the retreating portion 9 obtained by the calculation formula (11) is provided, the effect of sufficiently increasing the electron emission efficiency can be obtained. Recognize.

Further, FIG. 24 is a diagram in which the horizontal axis represents the work function Wf and the vertical axis represents the receding distance Lsat, where Vf = 12 V and the height T2 of the recess 7 = 20 nm. In any value of Wf = 3 to 6 eV, Lsat> Lsat _sim is satisfied, and if the amount of the retreating portion 9 obtained by the calculation formula (11) is provided, the effect of sufficiently increasing the electron emission efficiency can be obtained. Recognize.

  From the above results, it was confirmed by simulation that the receding distance Lsat necessary for sufficiently increasing the electron emission efficiency can be expressed by the calculation formula (11).

(Example 3)
An electron-emitting device provided with a protrusion 30 on the gate 5 shown in FIG. 25 was produced. 25A is a plan view, FIG. 25B is a cross-sectional view taken along the line AA ′ of FIG. 25A, and FIG. 25C is a view of FIG.

  In this example, the number of cathodes 6 is four, and the receding distance T8 is 100 nm.

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

  In this embodiment, as shown in FIG. 25, molybdenum (Mo), which is a cathode material, also adheres to the gate 5. The Ni release layer was formed excluding the region where the protrusion 30 was formed. The EB vapor deposition method was used as the Mo film forming method, and the substrate angle was set to 80 °. As a result, Mo was incident on the upper part of the gate 5 at 80 °, and the inclined surface (side surface) after the RIE processing of the insulating layer 3a of the element was set so that the incident angle was 20 °. The deposition rate was set so that the deposition was about 10 nm / min, and the two-minute deposition time was precisely controlled so that the Mo thickness on the slope was 20 nm.

  After forming the Mo film, unnecessary Mo was peeled off from the gate 5 by removing the Ni peeling layer deposited on the gate 5 using an etching solution composed of iodine and potassium iodide.

After peeling, a resist pattern was formed by photolithography so that the width T4 of the cathode 6 was 3 μm and the distance T7 between the cathodes 6 was 3 μm. Thereafter, the cathode 6 was processed using a dry etching technique. As the processing gas at this time, CF ₄ -based gas was used because molybdenum used as the cathode material was selected as a material for producing fluoride.

  As a result of cross-sectional TEM analysis of the obtained device, the shortest distance T13 of the gap 8 between the cathode 6 and the gate 5 was 8.5 nm on average.

  After the device was formed by the above method, the characteristics of the electron-emitting device were evaluated in the same manner as in Example 1.

  As a result, an element was obtained in which the average electron emission current Ie was 6.2 μA and the average electron emission efficiency was 15% at a driving voltage of 26 V.

  Considering this characteristic, it is presumed that the electron emission current is increased by the number of strips by increasing the number of cathodes 6.

  In the same manufacturing method, the distance T7 between the width T4 of the cathode 6 and the cathode 6 is set to 0.5 μm, the number of the cathodes 6 is increased by 100 times, and the width T5 of the protruding region of the gate 5 and the receding portion 9 are correspondingly increased. When the width was set to 0.5 μm, an electron emission amount of about 100 times was obtained. In the present invention in which a plurality of cathodes 6 are provided in this way, electrons can be preferentially emitted from the end portions of the respective cathodes 6, so that an electron beam having a more uniform electron beam shape than the conventional electron-emitting devices is provided. Can provide a source. That is, it is possible to eliminate the difficulty of controlling the electron beam shape based on the fact that the electron emission location is unspecified as in the conventional electron-emitting device, and to provide an electron beam source with a well-formed electron beam shape.

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. 26B 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, the comb-like processing is 100 per element, and 100 cathodes 6 are arranged per pixel.

<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, 100 strips of Mo were processed by photolithography and etching to form electron-emitting devices.

<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, in order to insulate the X-direction wiring 32 manufactured in the next step from the Y-direction wiring 33 described above, an insulating layer made of silicon oxide is provided below the X-direction wiring 32 described later and first. It arrange | positioned so that the formed X direction wiring 32 might be covered. 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 with the Y direction wiring 33 with the insulating layer interposed therebetween, and is connected to the electrode 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. 26B, a face plate 46 in which the fluorescent 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 Substrate 2 Electrode 3 Insulating member 3a, 3b Insulating layer 5 Gate 6 Cathode 7 Recessed part 8 Gap 9 Recessed part 10 R part 11 Anode 12 Protruding region 30 Protruding part

Claims (6)

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 at least a part of a region facing the cathode protrudes, and a gate end portion recedes across the protruding region. Electron beam equipment. The width of the protruding region of the gate is T5 [m], the width of the cathode is T4 [m], the shortest distance between the cathode tip and the gate is T13 [m], and the protruding region of the gate protrudes from the region facing the cathode. When the length of the part is T12 [m],
T5> T4
T12 <T13
The electron beam apparatus according to claim 1, wherein The height of the recess in the stacking direction of the gate and the insulating member is T2 [m], the receding distance of the receding portion is T8 [m], the work function of the cathode is Wf [eV], and the voltage applied between the cathode and the gate When the energy when one electron is accelerated by Vf [V] is EVf [eV],
T8 ≧ 6 × T2 × {1- (Wf / EVf)}
The electron beam apparatus according to claim 1 or 2.   4. 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.   The electron beam apparatus according to any one of claims 1 to 4, wherein at least a part of the insulating member corresponding to the receding portion of the gate is formed such that the surface recedes in the same manner as the receding portion.   6. 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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